Sampling Distributions

At a particular college, 78% of all students are receiving some kind of financial aid.The school newspaper selects a random sample of 100 students and 72% of the respondents say they are receiving some sort of financial aid. Which of the following is true?

•  78% is a population and 72% is a sample.
• 72% is a population and 78% is a sample
• 78% is a parameter and 72% is a statistic
• 72% is a parameter and 78% is a statistic

Tags

(SR.DSR.4.3

What happens to the shape of a sampling distribution of sample means as n increases?

• It becomes narrower and bimodal.
• It becomes narrower and more normal.
• It becomes wider and skewed right. 
• It becomes wider and more normal. 

Tags

(SR.DSR.4.3

These symbols represent the mean and standard deviation for which of the following distributions?

• The Population
• The Sample
• The Sampling Distribution

Tags

(SR.DSR.4.3

These symbols represent the mean and standard deviation for which of the following distributions?

• The Population

• The Sample

• The Sampling Distribution

Tags

(SR.DSR.4.3

In a national study on transportation patterns, 1,000 randomly selected adults will be asked the question: How many trips per week do you make to the grocery store? The sample mean will be computed. Let µ denote the population mean response to the question if everyone in the population is to be asked the question. Is the sample mean x unbiased for estimating µ?

• Yes, because for random samples the mean (expected value) of the sample mean x is equal to the population mean µ.

• Yes, because with a sample size of 1,000 the standard deviation of the sample mean x is small.

• Yes, because the wording of the question is not biased.

• No, because the sample mean x does not always equal the population mean µ.

• No, because number of trips to the grocery story is not normally distributed so the mean (expected value) of the sample mean x does not equal the population mean µ.

Tags

(SR.DSR.4.3

The mean and standard deviation of a population are 200 and 20, respectively. Sample size is 25. 
What is the standard deviation of the sampling distribution?

• 200
• 16
• 25
• 4

Tags

(SR.DSR.4.3

The mean and standard deviation of a population are 200 and 20, respectively. Sample size is 25. 
What is the mean of the sampling distribution?

• 200
• 16
• 25
• 4

Tags

(SR.DSR.4.3

The mean and standard deviation of a population are 200 and 20, respectively. 
What is the probability of selecting one data value less than 190?

• 69%
• 42%
• 31%
• 58%

Tags

(SR.DSR.4.3

The mean and standard deviation of a population are 200 and 20, respectively. 
What is the probability of selecting 100 data values with a mean greater than 202?

• 45%
• 36%
• 25%
• 16%

Tags

(SR.DSR.4.3

Employees at a large company can earn monthly bonuses. The distribution of monthly bonuses earned by all employees last year has mean 2.3 and standard deviation 1.3. Let z represent the standard normal distribution. If x represents the mean number of monthly bonuses earned last year for a random sample of 40 employees, which of the following calculations will give the approximate probability that x is less than 2 ?

• 
• 
• 
• 
• 

Tags

(SR.DSR.4.3