Aresearcher did a pilot sample of 25 individuals with a population standard deviation of 0.40. How many more must he survey to develop a 95% confidence interval that has 0.03 margin of error? (Note: Round - up your answer into whole number) A 543 B 518 658 D 683

Tina catches a 14-pound bass.  She does not know the population mean or standard deviation.  So she takes a sample of five friends and they say the last bass they caught was 9, 12, 13, 10, and 10 pounds.  Find the t and calculate a 95% (α = .05) confidence interval.

A sample of 20 bags of mulch had a mean weight of 52 pounds with a standard deviation of 3.8 pounds. Find the 95% confidence interval of the true mean. Show all your work for or explain how you obtained your answer in the space provided below.

A marine biologist would like to estimate the mean weight of all mahi mahi on the Treasure Coast, using a 99% confidence interval. The standard deviation of the weights of all mahi mahi on the Treasure Coast is known to be 8.2 pounds. How large a sample of mahi mahi should the marine biologist select so that the estimate is within 0.88 pounds of the true population mean. Round the solution up to the nearest whole number.  n=

You measure 25 turtles' weights, and find they have a mean weight of 46 ounces. Assume the population standard deviation is 3.2 ounces. Based on this, construct a 99% confidence interval for the true population mean turtle weight.Give your answers as decimals, to two places

You measure 38 backpacks' weights, and find they have a mean weight of 77 ounces. Assume the population standard deviation is 10.7 ounces. Based on this, what is the maximal margin of error associated with a 99% confidence interval for the true population mean backpack weight. Give your answer as a decimal, to two places H ounces

A random sample of 64 shoppers showed that they spend an average of $27.31 per visit at the Sunday Mornings Bookstore. The standard deviation of the population is $2.14. Find the 90% confidence interval of the true mean. Please include all work showing how you found your answer.

Researchers studied the mean egg length (in millimeters) for a bird population. After taking a random sample of eggs, they obtained a 95% confidence interval of (45,60). What is the value of the margin of error? Choose the correct answer below. A. 15 mm B. 52.5 mm O c. 7.5 mm O D. 1.96

Karen wants to advertise how many chocolate chips are in each Big Chip cookie at her bakery. She randomly selects a sample of 78 cookies and finds that the number of chocolate chips per cookie in the sample has a mean of 19.3 and a standard deviation of 2.1.   Find a 80% confidence interval for the number of chocolate chips per cookie for Big Chip cookies?   Round your answers to one decimal place.

You measure the weights of 41 textbooks and find they have a mean weight of 77 ounces. The standard deviation for weights of all textbooks is 5.1 ounces. Based on this, construct a 90% confidence interval for the true population mean textbook weight. Give your answers as decimals, to two places