TRUE OR FALSE

1. The linear correlation coefficient measures the strength of the linear association between two variables.
2. If the sample size for estimating a population mean increased, the width of the confidence interval will decrease.
3. The statement "The weight of an adult individual is 110 pounds" is an example of a point estimate.
4. Estimation means assigning values to a population parameter based on the values of a sample statistic.
5. For a specific confidence interval, the smaller the sample size, the larger the maximum error of estimate will be.
6. Regression line is used to estimate the change iny-variable for a one unit change inx-variable.
7. An estimator is consistent if, as the sample size increases, the value of the estimator approaches the value of the parameter.
8. The sampling error is the difference between the sample statistic and the population parameter.
9. A value used to estimate a population parameter is called a sample statistic.
10. An estimator is the sample statistic used to estimate a population parameter.
11. Suppose we want to find the confidence interval for a population mean. If the level of confidence is increased, say 95% to 99%, the width of the interval will also increase.
12. The value of the correlation is reported by a researcher to ber=0.4. This implies that thex-variable explains 20% of the variability in they-variable.
13. A good estimator is one that is unbiased, consistent and relatively efficient.
14. The three confidence intervals which are often used are 99%, 95% and 90%.
15. A magazine for vehicle reported that the correlation between vehicle weight and vehicle reliability is -0.45. This suggests that heavier vehicle tend to be less reliable.
16. Point estimates are preferred over interval estimates since a confidence interval can be specified.
17. An interval estimate always contains the population parameter.
18. A sample coefficient of correlation can range from -1.00 to 1.00.
19. Maximum error of estimate is the minimum difference between the point estimate of a parameter and the actual value of the parameter.
20. The value of a sample statistic is referred as the point estimate of the corresponding population parameter.

CHOOSE THE ANSWER BELOW.

a. positive correlation b. negative correlation c. no correlation

1. Cholesterol level and incidence of coronary heart disease.
2. IQ level and Grade Point Average.
3. Number of campaign materials used by marketing representatives and level of awareness of customers.
4. Number of television commercials and sales of its product.
5. Board Exam performance and eating habits.
6. Amount of time spent studying and final exam scores.
7. Income and expenditure.
8. Mileage a vehicle has been driven and selling price.
9. Outside temperature and ice cream sales.
10. Income and educational attainment.

In correlation analysis

a. we study the difference between two variables

b. we consider the intercept with thex-axis

c. we study the strength of relationship between two variables

The relationship between dependent and independent variables represented by the linear regression (simple) is

a parabola

B. curve

C. straight line

Which value of correlation coefficient indicates a stronger correlation than -0.60?

A. 0.45

B. 0.65

C. -0.40

D. 0

The variable used as the estimator is referred as

A. dependent variable

B. correlation coefficient

C. regression line

D. independent variable

A simple linear regression is a regression model that contains

A. one independent variable

B. one independent variable and one dependent variable

C. one dependent variable