6 (10)

A random sample of the amounts for 20 purchases was taken. The mean was $41.79, the standard deviation was $22.48. and the margin of error for a 95% condence interval was $10.52. Assume that t:_1 =2.0 for the 95% condence intervals. a) To reduce the margin of error to about $5. how large would the sample size have to be? b) How large would the sample size have to be to reduce the margin of error to $1.0? l. a) The new sample size should be I]. (Round up to the nearest integer.)