*Please Answer All*
1. A sample of 210 one-year-old baby boys in the United States had a mean weight of 23.8 pounds. Assume the population standard deviation is 3.0 pounds. What is the upper bound of the 90% confidence interval for the mean lifetime of the components? Round to two decimals.
2. Efficiency experts study the processes used to manufacture items in order to make them as efficient as possible. One of the steps used to manufacture a metal clamp involves the drilling of three holes. In a sample of 74 clamps, the mean time to complete this step was 48.9 seconds. Assume that the population standard deviation is 13 seconds. What is the lower bound of the 98% confidence interval? Round to one decimal place.
3. In a simple random sample of 57 electronic components produced by a certain method, the mean lifetime was 1,188 hours. Assume that component lifetimes are normally distributed with population standard deviation 53 hours. What is the upper bound of the 95% confidence interval for the mean lifetime of the components? Round to the nearest integer.
4. A college admissions officer takes a simple random sample of 106 entering freshmen and computes their mean mathematics SAT score to be 508. Assume the population standard deviation is 122. What is the lower bound of the 99% confidence interval? Round to the nearest integer.
*Please Answer All* 1. A sample of 210 one-year-old baby boys in the United States had...
Question 7 (4.2 points) A simple random sample of electronic components will be selected to test for the mean lifetime in hours. Assume that component lifetimes are normally distributed with population standard deviation of 20 hours. How many components must be sampled so that a 99% confidence interval will have margin of error of 6 hours? Write only an integer as your answer. Question 8 (5 points) Six measurements were made of the mineral content (in percent) of spinach, with...
According to the National Health Statistics Reports, a sample of 360 one-year-old baby boys in the United States had a mean weight of 25.5 pounds. Assume the population standard deviation is σ = 5.3 pounds. Construct a 99% confidence interval for the mean weight of one-year-old baby boys in the United States. Based on this confidence interval, is it likely that the mean weight of all one-year-old boys is less than 28 pounds?
Question 9 (4 points) A college admissions officer takes a simple random sample of 104 entering freshmen and computes their mean mathematics SAT score to be 471. Assume the population standard deviation is 121. What is the lower bound of the 99% confidence interval? Round your answer to the nearest integer. Write only a number as your answer.
Efficiency experts study the processes used to manufacture items in order to make them as efficient as possible. One of the steps used to manufacture a metal clamp involves the drilling of three holes. In a sample of 68 clamps, the mean time to complete this step was 54.5 seconds. Assume that the population standard deviation is 6 seconds. What is the lower bound of the 98% confidence interval?
Lifetime of electronics: In a simple random sample of 100 electronic components produced by a certain method, the mean lifetime was 125 hours. Assume that component lifetimes are normally distributed with population standard deviation - 20 hours. Round the critical value to no less than three decimal places. Part: 0/2 Part 1 of 2 (a) Construct a 90% confidence interval for the mean battery life. Round the answer to the nearest whole number. A 90% confidence interval for the mean...
A simple random sample of electronic components will be selected to test for the mean lifetime in hours. Assume that component lifetimes are normally distributed with population standard deviation of 30 hours. How many components must be sampled so that a 99% confidence interval will have margin of error of 2 hours?
Question 5 (1 point) Efficiency experts study the processes used to manufacture items in order to make them as efficient as possible. One of the steps used to manufacture a metal clamp involves the drilling of three holes. In a sample of 83 clamps, the mean time to complete this step was 56.6 seconds. Assume that the population standard deviation is 9 seconds. What is the lower bound of the 98% confidence interval? Round your answer to one decimal place...
A college admissions officer takes a simple random sample of 104 entering freshmen and computes their mean mathematics SAT score to be 490 . Assume the population standard deviation is 117 . What is the lower bound of the 99% confidence interval?
A college admissions officer takes a simple random sample of 102 entering freshmen and computes their mean mathematics SAT score to be 496 . Assume the population standard deviation is 118 . What is the lower bound of the 99% confidence interval?
Please help! A simple random sample of size n=20 is drawn from a population that is normally distributed. The sample mean is found to be x = 59 and the sample standard deviation is found to be S = 11. Construct a 95% confidence interval about the population mean. The lower bound is . The upper bound is . (Round to two decimal places as needed.)