Hi, I need help with these questions. Thank you

In a survey, 17 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $39.5 and standard deviation of $18.5. Estimate how much a typical parent would spend on their child's birthday gift (use a 80% confidence level). Give your answers to 3 decimal places. Express your answer in the format of a + E. Assume that a sample is used to estimate a population mean u. Find the 90% confidence interval for a sample of size 43 with a mean of 63.1 and a standard deviation of 13.2. Round your critical value to three decimal places for your calculations. Enter your final answer as an open-interval (i.e., parentheses) accurate to 1 decimal places. 90% C.I. = The body temperatures in degrees Fahrenheit of a sample of adults in one small town are: 99.5 98.6 96.4 98.3 99.2 96.6 97.5 96.3 99.4 97.2 96.9 99.7 96.8 Assume body temperatures of adults are normally distributed. Based on this data, find the 99% confidence interval of the mean body temperature of adults in the town. Enter your answer as an open-interval (i.e., parentheses) accurate to 3 decimal places. Assume the data is from a normally distributed population. 99%% C.I. = Isabella wants to advertise how many chocolate chips are in each Big Chip cookie at her bakery. She randomly selects a sample of 79 cookies and finds that the number of chocolate chips per cookie in the sample has a mean of 18.9 and a standard deviation of 1.9. What is the 99% confidence interval for the number of chocolate chips per cookie for Big Chip cookies? Assume the data is from a normally distributed population. Round answers to 3 decimal places where possible.