1. In a survey, 16 people were asked how much they spent on their child's last birthday...
Question:
1. In a survey, 16 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $38 and standard deviation of $7. Estimate how much a typical parent would spend on their child's birthday gift (use a 95% confidence level).
Give your answers to one decimal place. Provide the point estimate and margin or error.
_____________± _______________
2. Assume that a sample is used to estimate a population mean μμ. Find the 90% confidence interval for a sample of size 56 with a mean of 59.2 and a standard deviation of 13.2. Enter your answer as an open-interval (i.e., parentheses) accurate to one decimal place (because the sample statistics are reported accurate to one decimal place).
90% C.I. = _______________________
Answer should be obtained without any preliminary rounding. However, the critical value may be rounded to 3 decimal places.
Elementary Statistics Picturing the World
ISBN: 978-0134683416
7th edition
Authors: Ron Larson, Betsy Farber