Government data show that 7% of the american population are at least 75 years of age. to test a random-digit dialing device, you use the device to call randomly chosen residential telephones in your county. of the 290 members of the households contacted, 5% are 75 years or older. (a) is each of the boldface numbers a parameter or a statistic? 7%: statistic, 5%: statistic 7%: parameter, 5%: parameter 7%: parameter, 5%: statistic 7%: statistic, 5%: parameter (b) assume that your county's population is similar to the american population in age distribution. what are the mean and standard deviation of the sample proportion who are at least 75 years of age in samples of 290 respondents? μ = (use 2 decimal places) σ = (use 3 decimal places) (c) what is the probability that a random sample of 290 respondents would contain less than 5% of individuals at least 75 years of age? (use 3 decimal places)