Exam 7: Sampling and Sampling Distributions

A simple random sample of 8 employees of a corporation provided the following information. a.Determine the point estimate for the average age of all employees. b.What is the point estimate for the standard deviation of the population? c.Determine a point estimate for the proportion of all employees who are female.

Michael is running for president.The proportion of voters who favor Michael is 0.8.A simple random sample of 100 voters is taken. a.What are the expected value,standard deviation,and shape of the sampling distribution of? b.What is the probability that the number of voters in the sample who will not favor Michael will be between 26 and 30? c.What is the probability that the number of voters in the sample who will not favor Michael will be more than 16?

The following information was collected from a simple random sample of a population. The point estimate of the population standard deviation is

The life expectancy in the United States is 75 with a standard deviation of 7 years.A random sample of 49 individuals is selected. a.What is the probability that the sample mean will be larger than 77 years? b.What is the probability that the sample mean will be less than 72.7 years? c.What is the probability that the sample mean will be between 73.5 and 76 years? d.What is the probability that the sample mean will be between 72 and 74 years? e.What is the probability that the sample mean will be larger than 73.46 years?

From a population of 500 elements,a sample of 225 elements is selected.It is known that the variance of the population is 900.The standard error of the mean is approximately

There are 6 children in a family.The number of children defines a population.The number of simple random samples of size 2 (without replacement)which are possible equals

The average lifetime of a light bulb is 3,000 hours with a standard deviation of 696 hours.A simple random sample of 36 bulbs is taken. a.What are the expected value,standard deviation,and shape of the sampling distribution of $\bar{x}$ ? b.What is the probability that the average life in the sample will be between 2,670.56 and 2,809.76 hours? c.What is the probability that the average life in the sample will be greater than 3,219.24 hours? d.What is the probability that the average life in the sample will be less than 3,180.96 hours?

From a group of 12 students,we want to select a random sample of 4 students to serve on a university committee.How many different random samples of 4 students can be selected?

Students of a large university spend an average of $5 a day on lunch.The standard deviation of the expenditure is $3.A simple random sample of 36 students is taken. a.What are the expected value,standard deviation,and shape of the sampling distribution of the sample mean? b.What is the probability that the sample mean will be at least $4? c.What is the probability that the sample mean will be at least $5.90?

The following data was collected from a simple random sample of a population. The point estimate of the population mean

The sample mean is the point estimator of