Answer: 267.
Step-by-step explanation:
When there is no prior information for the population proportion, then the formula we use to find the sample size to estimate the confidence interval :
, where z* = Critical z-value and E + amrgin of error.
Let p = proportion of packages of ground beef sold at a particular store that have an actual fat content exceeding the fat content stated on the label.
Since , we have no prior information about p. so we use above formula
with E = 0.06 and critical value for 95% confidence =z* =1.96 [By z-table ] , we get
Hence, the required sample size is 267.