6.16
A population has distribution of unknown shape. The mean of the population is 3,500, and the standard deviation is 600.
a. If a sample of 100 values is selected randomly from this population, what is the probability that the sample mean will exceed 3,600?
b. If a sample of 200 is selected from the population what is the probability that the sample mean will exceed 3,600?
c. Compare your answer to parts a and b and explain why the two probabilities are different.

6.11
A population is normally distributed, with a mean of 1,000 and a standard deviation equal to 200.
a. Determine the probability that a random sample of size 5 selected from this population will have a sample mean less than 970?
b. Referring to part a, suppose a second sample of size 10 is selected. What is the probability that this sample will have a mean that is less than 970?
c. Why are the answers to parts a and b different? Discuss

6.17
A random sample of 100 items is selected from a population of size 350. What is the probability that the sample mean will exceed 200 if the population mean is 195 and the population standard deviation equals 20? Hint, use the finite correction factor, because the sample size is more than 5% of the population size!

The number of cars that travel through an intersection between noon and 1pm is measured for 30 consecutive days. The results of the 30 observations are: 61,62,63,63,64,64,66,66,67,68,68,68,68,69,69,69,69,70,70,70,70,71,71,72,73,74,74,75,76,and 79
Find: a.) Range
b.) Standard Deviation
c.) The population standar

If many samples of size 15 (that is, each sample consists of 15 items) were taken from a large normal population with a mean of 18 and variance of 5, what would be the mean, variance, standard deviationand shape of the distribution of sample means? Give reasons for your answers.
Note: Variance is the square of the standard d

If the sampled population has a mean of 48 and a standard deviation of 16, then the mean and the standard deviation for the sampling distribution of x -bar for n = 16 is?

A sample mean, sample size, and population standard deviation are given. Use the P-value approach to perform a one-mean z-test about the mean of the population from which the sample was drawn.
x bar= 78, n = 28, sigma = 11, Hnought: mu=72, Hone: mu>72 , alpha = 0.01
First find the proper z value then use this to find the

If the standard deviation of a population is 70 and we want the standard error (the standard deviation of the sample mean) to be 14, what is the number of samples that we need to take?

If you were designing a study which group, a population or a sample, would you collect data from and why? Provide an explanation regarding whether or not the standard deviation is a biased or unbiased estimate. When comparing the standard deviation to the variance, which do you prefer to interpret and why do you feel this way?