Alarge city newspaper periodically reports the mean cost of dinner for two people at restaurants in the city. the newspaper staff will collect data from a random sample of restaurants in the city and estimate the mean price using a 90 percent confidence interval. in past years, the standard deviation has always been very close to $35. assuming that the population standard deviation is $35, which of the following is the minimum sample size needed to obtain a margin of error of no more than $5 ? a) 90
b) 112
c) 133
d)147