please help me to solve this three questions with explanation. Thanks?

Suppose a survey of 275 executives is taken in an effort to determine what qualities are most important for an effective CEO to possess. The survey participants are off ered several qualities as options, one of which is "communicator," One hundred twenty-one of the surveyed respondents select "communicator" as the most important quality for an effective CEO. Use these data to construct a 98% confidenceinterval to estimate the population proportion of executives who believe that"communicator" is the most important quality of an effective CEO. what is the lower value of this interval? (Round the answers to 2 decimal places, e.g. 0.75.) D Question 2 5 pts A manufacturing plant produces steel rods. During one production run of 20,000 such rods, the specifications called for rods that were 46 cm in length and 3.8 cm in width. Fifteen of these rods making up a random sample were measured for length; the resulting measurements are shown here. Use these data to estimate the population variance of length for the rods. Assume rod length is normally distributed in the population. Construct a 99% confidence interval and provide the lower value of this interval. 44 cm 47 cm 43 cm 46 cm 46 cm 45 cm 43 cm 44 cm 47 cm 46 cm 48 cm 48 cm 43 cm 44 cm 45 cm (Round your answers to 2 decimal places, e.g. 1.75.) D Question 3 5 pts A random sample of size 39 is taken from a population of 200 members. The sample mean is 70 and the population standard deviation is 9. Construct a 96% confidence interval to estimate the population mean. What is the higher value of this interval? (Round confidence interval answers to 2 decimal places, e.g. 25.31