.An online retailer claims that 90% of all orders are shipped within 12 hours
of being received. A consumer group placed 121 orders of different sizes and at different
times of day; 102 orders were shipped within 12 hours.
1. Compute the sample proportion of items shipped within 12 hours.
2. Confirm that the sample is large enough to assume that the sample proportion
is normally distributed. Use p = 0.90, corresponding to the assumption that the
retailer’s claim is valid.
3. Assuming the retailer’s claim is true, find the probability that a sample of size 121
would produce a sample proportion so low as was observed in this sample.
4. Based on the answer to part (3), draw a conclusion about the retailer’s claim