Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = 1.5 for H0: µ = 15 centimeters and Ha: µ > 15 centimeters
> A psychologist suspects that breathing exercises can help people with depression. To decide whether he is correct, he identifies a group of subjects, watches them do the breathing exercises, and then asks them how they feel afterward.
> In a 3M Privacy Filters poll, 806 adults were asked to identify their favorite seat when they fly, and 61% of them chose a window seat. Test the claim that the majority of adults prefer window seats when they fly.
> The claim p > 0.5 can never be supported if the sample proportion p̂ is less than 0.5.
> The area to the right of the standard score z = 1.0 is 0.1587, so the P-value in a two-tailed test is 0.1587.
> In a hypothesis test involving a claim made about a population proportion, if there is sufficient evidence to reject the null hypothesis, then there may or may not be sufficient evidence to support the alternative hypothesis.
> In a test of the claim that a majority of Americans believe that human activity is the major cause of global warming, the null hypothesis is p = 0.5 and the alternative hypothesis is p > 0.5.
> A survey of 61,647 people included several questions about office relationships. Of the respondents, 26% reported that bosses scream at employees. The survey was an Elle/MSNBC.com survey to which Internet users chose whether to respond. It is valid to us
> A P-value of 0.00001 is obtained when sample data are used to test the claim that the majority of car crashes occur within 5 miles of home. What does this P-value tell us?
> A newspaper used images of cigarettes of different sizes to depict the percentages of adults who smoke in 2000 and in 2017. Which graphic would depict these data more objectively: a bar graph or images of two cigarettes of different sizes? Why?
> In hypothesis tests, if the significance level is 0.01, then the P-value is also 0.01.
> What is a type I error? What is a type II error?
> What do we mean by critical values for significance in a hypothesis test for the population mean? How do we use critical values for making decisions about hypothesis tests?
> Consumer Reports rated house paints according to how well they hold up to hot weather by conducting an experiment in which they applied the various paints to identical surfaces that were then left exposed to the same hot weather conditions for the same l
> When testing a claim about a population mean, what is a standard score for the sample mean?
> Briefly describe what each of the variables n, x‾, s, σ , and μ represent in hypothesis tests of a claim made about a population mean.
> H0: The mean length of a bolt in the suspension system of new Audi cars is 3.456 centimeters. Ha: The mean length of a bolt in the suspension system of new Audi cars is not equal to 3.456 centimeters.
> H0: The lottery is fair. Ha: The lottery is biased.
> H0: The defendant is not guilty. Ha: The defendant is guilty.
> H0: The patient is free of a particular disease. Ha: The patient has the disease.
> In a survey conducted by Kelton Research, 1004 adults were asked to identify the sounds that they find most annoying. In response, 279 chose jackhammers, 388 chose car alarms, 128 chose barking dogs, and 209 chose crying babies. An illustrator depicts th
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. A simple random sample of 40 salaries of NCAA football coaches has a mean of $415,953. The standard devi
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. When 70 convicted embezzlers were randomly selected, the mean length of prison terms was found to be 22.
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. The health of the bear population in Yellowstone National Park is monitored by periodic measurements tak
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. The mean birth weight of male babies born to 121 mothers taking a vitamin supplement is 3.67 kilograms w
> I plan to use a double-blind experiment to test the hypothesis that people will experience a decrease in their pulse rate if they exercise vigorously for 40 minutes every day,
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. According to the U.S. Department of the Treasury, the mean weight of a quarter is 5.670 grams. A random
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. Researchers developed a questionnaire to identify compulsive buyers. A random sample of 32 subjects who
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. A random sample of 40 new baseballs is obtained. Each ball is dropped onto a concrete surface, and the b
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. According to the Energy Information Administration (Federal Highway Administration data), the average ga
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. A simple random sample of 50 adults is obtained, and each person’s red blood cell count (in cells per mi
> Weekly instruction time for a school student in the United States is 22.2 hours compared to 26.9 hours in China. Is the difference meaningful? How could a graph be constructed so that the difference is greatly exaggerated?
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. The label on the cold medicine Dozenol lists 600 milligrams of acetaminophen per fluid ounce as an activ
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. A clinical trial was conducted to test the effectiveness of the drug Zopiclone for treating insomnia in
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. A random sample of 36 cans of cola is obtained and the contents are measured. The sample mean is 12.19 o
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. According to a study by the Centers for Disease Control, the national mean hospital stay after childbirt
> Use a 0.05 significance level and conduct a full hypothesis test using the four-step process described in the text. Be sure to state your conclusion. A Roper poll used a sample of 100 randomly selected car owners. Within the sample, the mean time of owne
> What is blinding, and why is it important in an experiment that is testing the effectiveness of a drug?
> Assume that you are testing the alternative hypothesis Ha: µ< 4.43. If the sample mean has a standard score of z = 0.5, what do you conclude? Why is it not necessary to actually conduct a formal hypothesis test?
> Assume that you are testing the alternative hypothesis Ha: µ > 54.2. If the sample mean has a standard score of z = -1.0, what do you conclude? Why is it not necessary to actually conduct a formal hypothesis test?
> Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = 2.8 for H0: µ = 18.9 feet and Ha: µ > 18.9 fe
> Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = -0.9 for H0: µ = 612 feet and Ha: µ < 612 fee
> The rate of inflation in the 1970s was much higher than it is today, so prices today must be lower overall.
> Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = -1.7 for H0: µ = 36.9 degrees and Ha: µ ≠ 36
> Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = -2.7 for H0: µ = 120.5 kilograms and Ha: µ ≠
> Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = -2.1 for H0: µ = 24.7 miles and Ha: µ ≠ 24.7
> Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = -1.9 for H0: µ = 0.55 liter and Ha: µ ≠ 0.55
> Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = 2.1 for H0: µ = 232 pounds and Ha: µ ≠ 232 p
> Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = 1.7 for H0: µ = 125 pounds and Ha: µ ≠ 125 p
> What is a placebo, and why is it important in an experiment to test the effectiveness of a drug?
> Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = 3.0 for H0: µ = 15 centimeters and Ha: µ > 15
> Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = -3.0 for H0: µ = 15 centimeters and Ha: µ < 1
> There’s been only a very slight rise in our stock price over the past few months, but I wanted to make it look dramatic so I started the vertical scale from the lowest price rather than from zero.
> Use Table A-1 to find the P-value that corresponds to the given standard score, and determine whether to reject the null hypothesis at the 0.05 significance level. Is the alternative hypothesis supported? z = -1.5 for H0: µ = 15 centimeters and Ha: µ < 1
> Find the value of the standard scores, z, and determine whether to reject the null hypothesis at a 0.05 significance level. The critical values can be found in Tables 9.1 and 9.2. Is the alternative hypothesis supported? H0: µ = 75.0 seconds, Ha: µ ≠ 75
> Find the value of the standard scores, z, and determine whether to reject the null hypothesis at a 0.05 significance level. The critical values can be found in Tables 9.1 and 9.2. Is the alternative hypothesis supported? H0: µ= 25.5 g, Ha: µ≠ 25.5 g, n
> Find the value of the standard score, z, and determine whether to reject the null hypothesis at a 0.05 significance level. The critical values can be found in Tables 9.1 and 9.2. Is the alternative hypothesis supported? H0: µ = 26.2 km Ha: µ ≠ 26.2 km,
> Find the value of the standard scores, z, and determine whether to reject the null hypothesis at a 0.05 significance level. The critical values can be found in Tables 9.1 and 9.2. Is the alternative hypothesis supported? H0: µ = 18.4 meters, Ha: µ 18.4
> Find the value of the standard scores, z, and determine whether to reject the null hypothesis at a 0.05 significance level. The critical values can be found in Tables 9.1 and 9.2. Is the alternative hypothesis supported? H0: µ = 52.2 kg, Ha: µ > 52.2 kg,
> Find the value of the standard scores, z, and determine whether to reject the null hypothesis at a 0.05 significance level. The critical values can be found in Tables 9.1 and 9.2. Is the alternative hypothesis supported? H0: µ = 20.5 seconds, Ha: µ < 20.
> In testing the effectiveness of a new vaccine, suppose that researchers used males for the treatment group and females for the placebo group. What is confounding, and how would it affect such an experiment?
> Find the value of the standard scores, z, and determine whether to reject the null hypothesis at a 0.05 significance level. The critical values can be found in Tables 9.1 and 9.2. Is the alternative hypothesis supported? H0: µ = 3.8 cm, Ha: µ < 3.8 cm, n
> Find the value of the standard scores, z, and determine whether to reject the null hypothesis at a 0.05 significance level. The critical values can be found in Tables 9.1 and 9.2. Is the alternative hypothesis supported? H0: µ = 5.50 grams, Ha: µ > 5.50
> I used an exponential scale because the data values for my categories ranged from 7 to 450,000,000.
> A handy mnemonic for interpreting the P-value in a hypothesis test is this: “If the P (value) is low, then the null must go.”
> Because the significance level is the probability of making a type I error, it is wise to select a significance level of zero so that there is no chance of making that error.
> When a consumer group is testing the claim that the mean amount of aspirin in tablets is 350 milligrams, it is extremely important not to wrongly reject a true null hypothesis. Thus, it is better to choose 0.01 than 0.05 for the significance level.
> A significance level of 0.05 indicates that the probability of making a type I error is 0.05.
> The principal claimed that the school’s mean SAT score was above 650. A hypothesis test seemed to back her up, but it later turned out that the mean score was exactly 650. Therefore, the test resulted in a type I error of wrongly rejecting the null hypo
> In testing a claim about a population mean, if the standard score for a sample mean is z = 0, then there is not sufficient sample evidence to support the alternative hypothesis.
> When conducting hypothesis tests, you need to consider a different set of critical values for two-tailed tests than for one-tailed tests.
> What is a P-value for a hypothesis?
> Define variable, variables of interest, explanatory variable, and response variable. How are the explanatory and response variables related to each other?
> What are the two possible outcomes of a hypothesis test, and what do they mean? Can such a test have an outcome of accepting the null hypothesis?
> I drew a map on which I scaled the lengths (from east to west) of different counties based on their numbers of family-owned farms, and found that a county with twice as many farms as another ended up looking four times as large.
> What is a null hypothesis and an alternative hypothesis, and what notation do we use to denote them? How do left-tailed, right-tailed, and two-tailed hypothesis tests differ?
> What is a hypothesis in statistics? What do we mean by a hypothesis test in statistics?
> A random sample of 100 births includes 35 male babies. Is this result significant at the 0.05 level? What is the P-value for this result? What would you conclude based on this result? Answer: Yes. The P-value of 0.002 is less than the significance level
> A random sample of 100 births includes 35 male babies. Is this result significant at the 0.01 level? What is the P-value for this result?
> A random sample of 100 births includes 40 male babies. Is this result significant at the 0.05 level? What is the P-value for this result?
> A random sample of 100 births includes 40 male babies. Is this result significant at the 0.01 level? What is the P-value for this result?
> A random sample of 100 births includes 45 male babies. Is this result significant at the 0.01 level? What is the P-value for this result?
> A random sample of 100 births includes 48 male babies. Is this result significant at the 0.05 level? What is the P-value for this result?
> A bookstore owner claims that the proportion of people who read books in print is greater than 0.25.
> What is a biased sample, and what is a major problem with it?
> You want to determine the percentage of people in this country with each of the four major blood types (A, B, AB, and O). What would be an effective sampling plan that accounts for differences among ethnic groups?
> A bookstore owner claims that the proportion of people who read books in print is not 0.23.
> A sales representative claim that quarters inserted into her vending machines have a mean weight less than 5.64 grams.
> A sales representative claims that quarters inserted into her vending machines have a mean weight of 5.64 grams.
> The quality control manager at a manufacturing company claims that the proportion of defective transistors is 0.03.
> The quality control manager at a manufacturing company claims that the proportion of defective transistors is greater than 0.03.
> A medical researcher wants to test the claim that healthy adults have a mean body temperature of 98.6°F.
> A medical researcher wants to test the claim that healthy adults have a mean body temperature less than 98.6°F.
> In testing a method of gender selection, 200 couples use a treatment designed to increase the likelihood of having a girl, and each couple has one baby. Answer the following questions without doing any calculations. a. If the 200 babies include exactly
> In testing a method of gender selection, 40 couples use a treatment designed to increase the likelihood of having a girl, and each couple has one baby. Answer the following questions without doing any calculations. a. If the 40 babies include exactly 22
> When interpreting a P-value of 0.009, a researcher states that the results are statistically significant because the P-value is very small, indicating that the results are not likely to occur by chance.
> What are geographical data? Identify at least two ways to display geographical data.
> What is a representative sample, and why is it important?
> The producer of a new song surveys 1000 consumers and finds that most of them are very enthusiastic about it, so she convinces the Sony recording company to promote the song.
> When interpreting a P-value of 0.45, a researcher states that the results are statistically significant because the P-value is less than 0.5, indicating that the results are not likely to occur by chance.
> A study is designed to determine the proportion of men who weigh more than 195 pounds, so the null hypothesis is µ = 195 pounds and the alternative hypothesis is µ > 195 pounds.
