Question

The mean value of land and buildings per acre from a sample of farms is ​$1300​, with a standard deviation of ​$100. The data set has a​ bell-shaped distribution. Assume the number of farms in the sample is 77. ​(a) Use the empirical rule to estimate the number of farms whose land and building values per acre are between ​$1200 and ​$1400. nothing farms ​(Round to the nearest whole number as​ needed.) ​(b) If 22 additional farms were​ sampled, about how many of these additional farms would you expect to have land and building values between ​$1200 per acre and ​$1400 per​ acre? nothing farms out of 22 ​(Round to the nearest whole number as​ needed.)

Answer 1

µ = 1300

sd = 100

a)

                                                   

                                                    = P(-1 < Z < 1)

                                                    = 0.68

Expected value = 77 * 0.68 = 52

b) Expected value = 22 * 0.68 = 15