Questions from Statistics Principles

Q: State whether or not the normal approximation to the binomial is appropriate

State whether or not the normal approximation to the binomial is appropriate in each of the following situations. (a) n = 90, p = .24 (b) n = 100, p = .03 (c) n= 120, p = .98 (d) n= 6 1, p = .40...

Q: Copy Figure 16 and add the standard score scale /

Copy Figure 16 and add the standard score scale Underneath the x-axis for n = 5, 12, 25. Notice how the distributions center on zero and most of the probability lies between z = -2 and z = 2.

Q: The median age of residents of the United States is 37.

The median age of residents of the United States is 37.2 years. If a survey of 200 residents is taken, approximate the probability that at least 110 will be under 37.2 years of age.

Q: The unemployment rate in a city is 7.9%. A

The unemployment rate in a city is 7.9%. A sample of 300 persons is selected from the labor force. Approximate the probability that (a) Less than 18 unemployed persons are in the sample. (b) More th...

Q: A survey reports that 96% of the people think that violence

A survey reports that 96% of the people think that violence has increased in the past five years. Out of a random sample of 50 persons, 48 expressed the opinion that citizens have become more violent...

Q: The weekly amount spent by a small company for in-state

The weekly amount spent by a small company for in-state travel has approximately a normal distribution with mean $1450 and standard deviation $220. What is the probability that the actual expenses wil...

Q: In a large midwestern university, 30% of the students live

In a large midwestern university, 30% of the students live in apartments. If 200 students are randomly selected, find the probability that the number of them living in apartments will be between 55 an...

Q: Suppose that 20% of the trees in a forest are infested

Suppose that 20% of the trees in a forest are infested with a certain type of parasite. (a) What is the probability that, in a random sample of 300 trees, the number of trees having the parasite will...

Q: For each case, list the values of X and f (

For each case, list the values of X and f (x) and examine if the specification represents a probability distribution. If it does not, state what properties are violated. (a) f( x ) = 1/6 (x – 1) for x...

Q: Use a computer program to make a normal-scores plot for

Use a computer program to make a normal-scores plot for the volume of timber data in Table 4. (Courtesy of Professor Alan Ek) Comment on the departure from normality displayed by the normal-scores plo...