aianjie

 

AIM 4: Describe the key properties of the t-distribution, chi-square distribution, and F-distribution.

1、Which statement best describes the properties of Student’s t-distribution? The t-distribution is:

A) symmetrical, defined by a single parameter and is less peaked than the normal distribution.

B) symmetrical, defined by two parameters and is less peaked than the normal distribution.

C) skewed, defined by a single parameter and is more peaked than the normal distribution.

D) skewed, defined by a single parameter and is less peaked than the normal distribution

aianjie

 

The correct answer is A

The t-distribution is symmetrical like the normal distribution but unlike the normal distribution is defined by a single parameter known as the degrees of freedom and is less peaked than the normal distribution.

aianjie

 

AIM 3: Define the central limit theorem.

1、The central limit theorem concerns the sampling distribution of the:

A) sample mean.

B) population mean.

C) sample standard deviation.

D) population standard deviation.

aianjie

 

The correct answer is A

The central limit theorem tells us that for a population with a mean m and a finite variance σ2, the sampling distribution of the sample means of all possible samples of size n will approach a normal distribution with a mean equal to m and a variance equal to σ2 / n as n gets large.

aianjie

 

2、The central limit theorem states that, for any distribution, as n gets larger, the sampling distribution:

A) becomes larger.

B) becomes smaller.

C) approaches the mean.

D) approaches a normal distribution.

aianjie

 

8、If n is large and the population standard deviation is unknown, the standard error of the sampling distribution of the sample mean is equal to the:

A) population standard deviation divided by the sample size. 

B) sample standard deviation divided by the square root of the sample size.

C) population standard deviation multiplied by the sample size.

D) sample standard deviation divided by the sample size. 

aianjie

 

The correct answer is

The formula for the standard error when the population standard deviation is unknown is:

 

 

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[2008] Topic 5: Some Important Probability Distributions 相关习题

2009-6-25 12:47

aianjie

 

The correct answer is A

 

 

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[2008] Topic 5: Some Important Probability Distributions 相关习题

2009-6-25 12:46

aianjie

 

The correct answer is B

 

 

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[2008] Topic 5: Some Important Probability Distributions 相关习题

2009-6-25 12:44

aianjie

 

7、The population mean for equity returns is 14 percent with a standard deviation of 2 percent. If a random sample of 49 returns is drawn, what is the standard error of the sample mean?

A) 0.29%.

B) 0.04%.

C) 2.00%.

D) 7.00%.