Solve the all maths:

\fQ2. A psychologist claims that the mean age at which children start walking is 18 months. Mahz wanted to check if this claim is true. He took a random sample of St] children and found that the mean age at which these children started walking was 2t] months. It is knotvn that the ages at which all children start walking are approximately normally distributed with a standard deviation of 4 months. Test that the mean age at which all children start walking is greater than 13 months at 5% level of signicance. 03 Maria and Ellen both specialize in throwing the javelin. Maria thrmvs the javclin a mean distance of EDI] feet with a standard deviation of ill feet, whereas Ellen thro'Ws the javelin a mean distance of Eli] feet with a standard deviation of 12 feet. Assume that the distances each of these athletes thro'Ws thejavelin are normallyr distributed with these population means and standard deviations. The average distance for maria is 135 feet and for Ellen is 19? feet based on random samples of 120 throws and 14D throws, respectively. Test at the 1% signicance level that Maria's threw is longer than Ellen's? Q4 Aeeording to a Nationwide Mutual Insurance Company Driving While Distracted SUrvey conducted in 21121}, 16% of the drivers interviewed said that they have talked on their cell phones while driving [The New York Times. January 19, 221}. The survey included drivers aged 13 to 65 years selected from 52 states. Assume that this result holds true for the 2020 population of all such drivers in the United States. In a recent random sample of 1250 drivers aged 18 to 65 years selected from the United States, Ella/ii said that they have talked on their cell phones while driving. Test at 1% level of signicance the hypothesis that the cunent percentage of such drivers who have talked on their cell phones while driving is greater than from T5%. 05 A company wanted to know if attending a course on \"how to he a successful salesperson\" can increase the average sales of its employees. The company sent tea of its salespersons to attend this course. The following table gives the 1-week sales of these salespersons before and after they attended this course. Constmot a 93% condence intewal For the mean .ttd ofthe population paired differences. Using the 1% signicance leyel,r can you conclude that the mean weekly sales for all salespersons increase as a result of attending this course? Assume that the population of paired differences has a normal distribution