EXERCISES SAMPLING DISTRIBUTIONS

EXERCISES SAMPLING DISTRIBUTIONS

Multiple Choice

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

• The Population
• The Sample
• The Sampling Distribution

Multiple Choice

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

Multiple Choice

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

• The Population
• The Sample
• The Sampling Distribution

Multiple Choice

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

Multiple Choice

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 ?

Multiple Choice

What is the standard deviation of the distribution?

• 1010

• 20

• 60

• √20

Multiple Choice

The average stock price for companies making up the S&P500 is $30, and the standard deviation is $8.20. Assume the stock prices are normally distributed.

a) What is the probability that a company will have a stock price at least $40?

• 0.1457

• 0.1112

• 0.2256

• 0.1245

Multiple Choice

Given that z is a standard normal random variable, compute the following probabilities P(0 < z < 0.83), P(-1.57 < z < 0),

P(z > 0.44), P(z < 1.20)

• 0.0021, 0.4456, 0.2569, 0.4478

• 1.0025, 0.4418, 0.8855, 0.2356

• 0.2967, 0.4418, 0.3300, 0.8849

• 0.4412, 0.1145, 0.3325, 0.3312

Multiple Choice

The number of points scored by a team during a basketball game.

• Discrete
• Continuous

Multiple Choice

The weight of a newborn infant.

• Discrete
• Continuous

Multiple Choice

Suppose that a town has total 10,000 6th grade students and average weight of them is found to be 80 pounds, having a standard deviation of 20 pounds. If all the possible samples of 50 students are drawn out of the population of 10,000, then find the average weight and standard deviation of the sample distribution of the mean.

• 80 pounds, 2.83 pounds

• 80 pounds, 1.45 pounds

• 50 pounds, 2.83 pounds

• 50 pounds, 1.45 pounds

Multiple Choice

Which of the following gives the standard deviation of a sampling distribution?

• σ/√n
• σ/n
• σ/(n-1)
• σ/[ (√n)-1 ]

Multiple Choice

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%

Multiple Choice

The mean and standard deviation of a population are 200 and 20, respectively. 
What is the probability of selecting 64 data values with a mean between 195 and 200?

• 41%%
• 48%
• 1.5%
• 0.5%

Multiple Choice

The mean and standard deviation of a population are 200 and 20, respectively.

What is the probability of selecting 25 data values with a mean less than 190?

• 69%

• 0.6%

• 31%

• 99%