In designing a sample survey of a population with equal numbers of males and females, a pilot sample is taken which indicates that males have a higher mean of the quantity of interest than females but lower variance.Question 13Which one of the following would produce the most accurate estimate of the population mean when a larger sample is taken?Sampling equal numbers of males and femalesSampling proportionately more males than females, weighting results accordinglySampling proportionately more females than males, weighting results accordinglyCarrying out a purely random sample without regard to gender

A sample is taken from a population of 10,000 to estimate the mean value of a quantity of interest for that population.Question 18Assuming all those sampled produce a response, which one of the following is NOT a valid statement?The larger the sample size the more accurate will be the estimate of the population mean valueFor any given sample size, if the population had been 20,000 rather than 10,000 the accuracy of the estimate of the mean value would have been significantly lower.The greater the variance of the quantity of interest in the population, the less accurate will be the estimate of the population mean valueThe width of any confidence interval for the estimate of the population mean will be halved if the sample size is quadrupled

A social scientist wishes to conduct a survey. She plans to ask a yes/no question to a random sample from the U.S. adult population. One proposal is to select 100 people; another proposal is to select 900 people.If the study were conducted repeatedly (selecting different samples of people each time), which one of the following would be true regarding the resulting sample proportions of "yes" responses? Different sample proportions would result each time, but for sample size 900 they would be centered (have their mean) at the true population proportion, whereas for sample size 100 they would not. For either sample size, using the same size each time, as long as the sampling is done with replacement, their mean would be 0. Different sample proportions would result each time, but for either sample size, they would be centered (have their mean) at the true population proportion. Different sample proportions would result each time, but for sample size 100 they would be centered (have their mean) at the true population proportion, whereas for sample size 900 they would not.

Sam and Carmen want to find the mean weight of cats at their local pet adoption center. So they each randomly select cats at the shelter and measure the weights.The results are shown below (in pounds). Use the data to answer the questions.Sam's sample:10, 15, 12, 11, 20Carmen's sample:5, 13, 7, 11(a) What is the sample size for Sam's sample?(b) What is the sample size for Carmen's sample?(c) Suppose you had to choose one sample to estimate the mean.Which sample is more likely to give a good estimate of the mean?Sam's sampleCarmen's sampleWhy?It has the smaller mean.It has the larger mean.It has the smaller sample size.It has the larger sample size.

For the following, identify which type of sampling technique was used.A company has 800 female employees and 200 male employees. You want to ensure that the sample reflects the gender balance of the company, so you use random sampling on each gender group, selecting 80 women and 20 men.

A social scientist wishes to conduct a survey. She plans to ask a yes/no question to a random sample from the U.S. adult population. One proposal is to select 100 people; another proposal is to select 900 people.Which one of the following is true regarding the standard deviation of the sampling distribution of the sample proportion, p̂, of "yes" responses?Group of answer choicesThe standard deviation of the sampling distribution will be the same for both sample sizes.The standard deviation of the sampling distribution will be 3 times larger with sample size 100.The standard deviation of the sampling distribution will be 9 times smaller with sample size 100.The standard deviation of the sampling distribution will be 9 times larger with sample size 100.The standard deviation of the sampling distribution will be 3 times smaller with sample size 100.