TrueFalse problem Circle the answer Do not write T or F just

True/False problem. Circle the answer. (Do not write T or F; just circle.) (T, F) In a regression study, if the correlation coefficient (r) is larger, we can say the two related variables have a stronger relationship between them. (T, F) When we compare true mean values of three samples to know if they are the same, we cannot use a t-test, but we need to use an ANOVA analysis. (T, F) Let the expected value of random variable X is 10, and the expected value of random variable Y is 20. Then the expected value of 5X + 3Y is larger than 100. (T, F) We call a significance level of a statistics test a confidence level. 1. Short answers. We are to compare the effect of amount of water taken on the weight of people. To test this, we had subjects of 20 people to have 5 oz. of water a day for 20 days. After that, we had the same subjects to have 50 oz. of water a day for 20 days. What type of test would be good for this purpose? Get the answer from the lecture or textbook. We are comparing average income of two groups: plumber and carpenter. We want to test if the mean values of the two populations are the same. List two conditions for a z-test.

Solution

a. False.

correlation coefficient lies between -1 to +1. if the correlaiton is close to -1 or +1 we can say that the relationship is strong.

b. True. t-test used to test the difference of means between two samples . if more than two samples we use ANOVA.

c. Given E(X)=10; E(Y)= 20; E(5X+3Y)=5*10+3*20=110 which is greater than 100

So the statement is \"True\"

d. False