Problem 6. Determine if the following statements are true or false. Please circle one. (4 pts for correct answer) 6a} The width of a condence interval is equal to twice the margin of error. TRUE FALSE 6b) A simple regression model is used to forecast sales with advertising expenditures. The regression output indicates that the coefficient of advertising expenditures is positive and statistically significant. The output also indicates that the correlation between sales and advertising expenditures is 0.9132. Based on these results, we can conclude that spending more on advertising causes sales to go up. TRUE FALSE 6c) If a 95% confidence interval for the mean number of hours that students study per week is [18 23], then there is a 95% probability that a randomly selected student will study between 18 to 23 hours per week. TRUE FALSE 6d) If the level of confidence increases from 90% to 95%, the margin of error will increase TRUE FALSE 62) if the correlation between random variables X and Y is +0.8, then when X increases by 1, Y increases by 0.8. TRUE FALSE 61) RSquare determines whether or not the overall regression equation is statistically significant. TRUE FALSE 6g) Type 2 error in hypothesis testing is failing to reject the null hypothesis when it is false