er a population of 1024 mutual funds that primarily invest in large companies. You have determined that u, the mean one-year total percentage return achieved by all the funds, is 9.80 and th omplete (a) through (c). rding to the empirical rule, what percentage of these funds is expected to be within ±2 standard deviations of the mean?

Suppose the mean monthly return on a T-Bill is 0.5% with a standard deviation of 0.58%. Sup-pose we have another investment Y with a 1.5% mean monthly return and standard deviationof 6%. Which of the two investments o ers less risk in terms of investment.

Accrotime is a manufacturer of watches. Accotime researchers have shown that watches hwe an average life of 28 months before certain electronic components deteriorate causing the watch to become unreliable. The standard deviation of watch lifetimes is 5 months and the distribution is noemal. If Accrotime guarantees a full refund of any defective watch for 1.5 years after the purchase, what percentage of total production will the company expect to replace? Write your answer as a percentage rounded to 1 decimal place. For the toolbar, Press ALT+F10 (PC) or ALT+FN+F10 OMCA) 0 WOAOS POWEASD BY TINY

Biological oxygen demand (BOD) is a pollution index that is monitored in the treated effluent of paper mills. A certain paper mill has taken 31 samples over the past 3 months. The mean and standard deviation for the sample data are 3.42 and 0.728 ppm respectively. The mill would like to see if this sample indicates that the true average BOD in their treated effluent exceeds the targeted 3.00 ppm. Let ? = 0.05. A) The test statistic, (ttest), for this data set is: Note: Round your answer to the nearest hundredth.B) The p-value is: C) The statistical decision and corresponding English interpretation for this study are: Fail to reject Ha: conclude that the true BOD in treated effluent exceeds 3 ppmFail to reject Ho: we cannot conclude that the true BOD in treated effluent exceeds 3 ppm    Reject Ha: we cannot conclude that the true BOD in treated effluent exceeds 3 ppmReject Ho: conclude that the true BOD in treated effluent exceeds 3 ppm