Business 1 An estimator is called

1. An estimator is called consistent if its variance and standard deviations consistently remain the same

regardless of changes in the sample size.

True

False

2. When determining the sample size n, if the value found for n is 79.2, we would choose to sample 79

observations.

True

False

3. The larger the p-value, the more the chance of rejecting the null hypothesis.

True

False

4. A fastener manufacturing company uses a chi-square goodness of ‘t test to determine if a population of all

lengths of ¼ inch bolts it manufactures is distributed according to a normal distribution. If we reject the null

hypothesis, it is reasonable to assume that the population distribution is at least approximately normally

distributed.

True

False

5. The chi-square distribution is a continuous probability distribution that is skewed to the left.

True

False

6. The error term in the regression model describes the e.ects of all factors other than the independent

variables on y (response variable).

True

False

7. When constructing a con’dence interval for a sample proportion, the t distribution is always appropriate if

the sample size is small.

True

False

8. When the level of con’dence and sample standard deviation remain the same, a con’dence interval for a

population mean based on a sample of n=100 will be narrower than a con’dence interval for a population

mean based on a sample of n=50.

True

False

9. The sampling distribution of the sample mean is always normally distributed according to the Central Limit

Theorem.

True

False

10. The error term is the di.erence between the observed value of the dependent variable and the predicted

value of the dependent variable.

True

False

11. We do not need to perform the continuity correction if the population is 20 times or more than the sample

size.

True

False

12. For a continuous distribution, Probability of (X greater than or equal to 10) is less than the probability of

(X greater 10)

True

False

13. In a regression model the population of potential error terms is assumed to have a t-distribution.

True

False

14. The least squares simple linear regression line minimizes the sum squares of the vertical deviations

between the line and the data points.

(Points : 8)

True

False

15. In testing the di.erence between two means from two independent populations, the sample sizes do not

have to be equal to be able to use the Z statistic.

True

False

16. To investigate the rate at which employees with cancer are ‘red or laid o., a telephone survey was taken

of 100 cancer survivors who worked while undergoing treatment. Seven (7) were either ‘red or laid o. due to

their illness. Construct a 90% con’dence interval for the true percentage of all cancer patients who are ‘red

or laid o. due to their illness.

[0.0000 0.2034]

[0.0371 0.1029]

[0.0039 0.1361]

[0.0078 0.1400]

[0.0278 0.1122]

17. The area under the normal curve between z=2 and z=3 is ________________ the area under the normal

curve between z=1 and z=2.

Greater than

Less than

Equal to

Answers 1, 2, or 3 depending on the value of the Mean

Answers 1, 2, or 3 depending on the value of the Standard Deviation

18. For a given multiple regression model with three independent variables, the value of the adjusted

multiple coeCcient of determination is _________ less than R .

Always

Sometimes