1 The average mean toll for telephone calls to South America

Last updated: 10/24/2023

1 The average mean toll for telephone calls to South America is 85 the standard deviation is 10 Assuming that the tolls are normally distributed 1 a between what two values symmetrically distributed 99 of calls fall 2 b what is the toll in dollars and cents that is exceeded by 98 of the callers 3 c with 99 confidence what should the sample size be if sampling error is within 2