Questions from Statistics

Q: What is a sample mean? What is a sample proportion?

What is a sample mean? What is a sample proportion? Summarize the notation used for these statistics.

Q: How does the sample size affect how close to normal a distribution

How does the sample size affect how close to normal a distribution of either sample means or sample proportions will be? What are the means and standard deviations of the distributions in each case?

Q: I selected three different samples of size n = 10 drawn from

I selected three different samples of size n = 10 drawn from the 1500 students at my school, and with these I constructed the sampling distribution.

Q: a. In about what year did (will) the population

a. In about what year did (will) the population of 45- to 54-year-olds peak as a percentage of the population? b. In about what year did (will) the population of over 65-year-olds peak as a percentage...

Q: Based on our sample, the 95% confidence interval for the

Based on our sample, the 95% confidence interval for the mean amount of television watched by adult Americans is 2.5 to 2.7 hours per day. Therefore, there is 95% chance that the actual mean for the p...

Q: An engineering student measures the strength of fingers used to push buttons

An engineering student measures the strength of fingers used to push buttons by testing her own family members.

Q: Based on our sample, the 95% confidence interval for the

Based on our sample, the 95% confidence interval for the mean amount of television watched by adult Americans is 2.5 to 2.7 hours per day. Therefore, 95% of all Americans watch between 2.5 and 2.7 hou...

Q: Based on our sample, the 95% confidence interval for the

Based on our sample, the 95% confidence interval for the mean amount of television watched by adult Americans is 2.5 to 2.7 hours per day. Therefore, there is a 95% chance that the mean for all Americ...

Q: Although it made our study more expensive, we chose a larger

Although it made our study more expensive, we chose a larger sample size in order to have a smaller margin of error.

Q: One study involved a sample of people’s body temperatures and it resulted

One study involved a sample of people’s body temperatures and it resulted in this 95% confidence interval for the mean: 98.1 ⁰F