Choose the correct answer of each number.
1. With sample size of 250, sample mean of 9.7,standard deviation of 1.15 and confidence level of 99%, the Confidence Interval is?
a. With 99% confidence the population mean is between 9.51 and 9.89, based on 250 samples."
b. With 90% confidence the population mean is between 9.51 and 9.89, based on 250 samples."
c. With 95% confidence the population mean is between 9.15 and 9.98, based on 250 samples."
d. With 99% confidence the population mean is between 9.15 and 9.98, based on 200 samples."
2. An analyst hired by the multinational company to study the sales data of its more than 75 stores worldwide. You used regression analysis between $ sales (y) and $ advertising (x1) and $ salary of sales representatives (x2) across all the branches. You obtained the following regression function : y = 6000 + 8.5x1-1.6x2.
If the advertising budgets of one of the branches of the corporation is $12,000 and the salary of sales representatives is $2,500, then what will be the predicted sales?
a. $102,000
b. $6000
c. $112,000
d. $104,000
3. A one-sided significance test gives a P-value of 0.03. From this we can?
a. Reject the null hypothesis with 96% confidence.
b. Say that the probability that the null hypothesis is true is 0.03.
c. Reject the null hypothesis with 97% confidence.
d. Say that the probability that the null hypothesis is false is 0.03.