Question

1. Jose wants to advertise how many chocolate chips are in each Big Chip cookie at his bakery. He randomly selects a sample of 51 cookies and finds that the number of chocolate chips per cookie in the sample has a mean of 10.7 and a standard deviation of 2.6. What is the 90% confidence interval for the number of chocolate chips per cookie for Big Chip cookies? Assume the data is from a normally distributed population ________<M<_________

2.In a survey, 27 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $40.6 and standard deviation of $3.7. Estimate how much a typical parent would spend on their child's birthday gift (use a 99% confidence level). Give your answers to 3 decimal places.

Express your answer in the format of ¯xx¯ ±±  E.
$ _____±±______ $

3.

Answer 1

1)

from above 90% confidence interval =10.09 < M < 11.31

2)

99% confidence level = 40.6 -/+ 1.979