Hi, I need help with this please. Thanks.

In an article in Marketing Science. Silk and Berndt investigate the output of advertising agencies. They describe ad agency output by finding the shares of dollar billing volume coming from various media categories such as network television, spot television, newspapers, radio, and so forth. (a) Suppose that a random sample of 406 US. advertising agencies gives an average percentage share of billing volume from network television equal to 7.45 percent, and assume that oequals 1.44 percent. Calculate a 95 percent confidence interval for the mean percentage share of billing volume from network television for the population of all US. advertising agencies. (Round your answers to 3 decimal places.) The 95 percent condence interval is [I I I I (b) Suppose that a random sample of 406 US. advertising agencies gives an average percentage share of billing volume from spot television commercials equal to 12.42 percent, and assume that 0 equals 150 percent. Calculate a 95 percent confidence interval for the mean percentage share of billing volume from spot television commercials for the population of all US. advertising agencies. (Round your answers to 3 decimal places.) (c) Compare the confidence intervals in parts a and b. Does it appear that the mean percentage share of billing volume from spot television commercials for US. advertising agencies is greater than the mean percentage share of billing volume from network television? Explain. I I , condence interval in (b) is totally I lthe condence interval in (a)