Exam 8: Sampling Distributions

A farmer was interest in determining how many grasshoppers were in his field. He knows that the distribution of grasshoppers may not be normally distributed in his field due to growing conditions. As he drives his tractor down each row he counts how many grasshoppers he sees flying away. After several rows he figures the mean number of flights to be 57 with a standard deviation of 12. What is the probability of the farmer will count 52 or fewer flights on average in the next 40 rows down which he drives his tractor?

A farmer was interested in determining how many grasshoppers were in his field. He knows that the distribution of grasshoppers may not be normally distributed in his field due to growing conditions. As he drives his tractor down each row he counts how many grasshoppers he sees flying away. After several rows he figures the mean number of flights to be 57 with a standard deviation of 12. What is the probability of the farmer will count 60 or more flights on average in the next 40 rows down which he drives his tractor?

Determine and from the given parameters of the population and the sample size. Round the answer to the nearest thousandth where appropriate. -? = 69, ? = 24, n = 64

According to a study conducted in one city, 34% of adults in the city have credit card debts of more than $2000. A simple random sample of adults is obtained from the city. Describe the sampling distribution of , the sample proportion of adults who have credit card debts of more than $2000.

The amount of money collected by a snack bar at a large university has been recorded daily for the past five years. Records indicate that the mean daily amount collected is $6000 and the standard deviation is $400. The distribution is skewed to the right due to several high volume days (including football game days). Suppose that 100 days were randomly selected from the five years and the average amount collected from those days was recorded. Which of the following describes the sampling distribution of the sample mean?

Determine and from the given parameters of the population and the sample size. Round the answer to the nearest thousandth where appropriate. -? = 31, ? = 8, n = 15

The standard error of the mean is given by

Describe the sampling distribution of . -N = 20,000, n = 550, p = 0.2

What are the values of and for the sampling distribution of the sample mean shown?

What are the values of and for the sampling distribution of the sample mean shown?

A farmer was interested in determining how many grasshoppers were in his field. He knows that the distribution of grasshoppers may not be normally distributed in his field due to growing conditions. As he drives his tractor down each row he counts how many grasshoppers he sees flying away. After several rows he figures the mean number of flights to be 57 with a standard deviation of 12. What is the probability of the farmer will count 52 or fewer flights or 60 or more flights on average in the next 40 rows down which he drives his tractor?

A simple random sample of size n = 1240 is obtained from a population whose size is and whose population proportion with a specified characteristic is Describe the sampling distribution of .