Question

Suppose babies born in a large hospital have a mean weight of 4088 grams, and a variance of 55,696. If 128 babies are sampled at random from the hospital, what is the probability that the mean weight of the sample babies would differ from the population mean by less than 41 grams? Round your answer to four decimal places.

The diameters of ball bearings are distributed normally. The mean diameter is 66 millimeters and the variance is 25. Find the probability that the diameter of a selected bearing is less than 71 millimeters. Round your answer to four decimal places.

Calculate the standard score of the given X value, X=57.5, where μ=50.1 and σ=45.1. Round your answer to two decimal places.

A random sample of 10 fields of corn has a mean yield of 37.1 bushels per acre and standard deviation of 5.91 bushels per acre.

Determine the 98% confidence interval for the true mean yield. Assume the population is approximately normal. Step 1 of 2: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places. A random sample of 10 fields of corn has a mean yield of 37.1 bushels per acre and standard deviation of 5.91 bushels per acre. Determine the 98% confidence interval for the true mean yield. Assume the population is approximately normal.

Step 2 of 2: Construct the 98% confidence interval. Round your answer to one decimal place.

Suppose a batch of steel rods produced at a steel plant have a mean length of 178 millimeters, and a standard deviation of 12 millimeters. If 76 rods are sampled at random from the batch, what is the probability that the mean length of the sample rods would be less than 177.44 millimeters? Round your answer to four decimal places.

Suppose a batch of steel rods produced at a steel plant have a mean length of 178 millimeters, and a standard deviation of 12 millimeters. If 76 rods are sampled at random from the batch, what is the probability that the mean length of the sample rods would be greater than 177.44 millimeters? Round your answer to four decimal places.

Calculate the standard score of the given X value, X=88.3, where μ=87.8 and σ=87.4 and indicate on the curve where z will be located. Round the standard score to two decimal places. In a random sample of 9 residents of the state of Florida, the mean waste recycled per person per day was 2.4 pounds with a standard deviation of 0.75 pounds. Determine the 80% confidence interval for the mean waste recycled per person per day for the population of Florida. Assume the population is approximately normal.

Step 1 of 2: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places. In a random sample of 9 residents of the state of Florida, the mean waste recycled per person per day was 2.4 pounds with a standard deviation of 0.75 pounds. Determine the 80% confidence interval for the mean waste recycled per person per day for the population of Florida. Assume the population is approximately normal.

Step 2 of 2: Construct the 80% confidence interval. Round your answer to one decimal place.

A marketing research company desires to know the mean consumption of meat per week among males over age 27. They believe that the meat consumption has a mean of 3.2 pounds, and want to construct a 90% confidence interval with a maximum error of 0.07 pounds. Assuming a standard deviation of 0.9 pounds, what is the minimum number of males over age 27 they must include in their sample? Round your answer up to the next integer.

Find the area under the standard normal curve to the right of z=1.56. Round your answer to four decimal places, if necessary.

The weights of steers in a herd are distributed normally. The standard deviation is 300 lbs and the mean steer weight is 1100 lbs. Find the probability that the weight of a randomly selected steer is greater than 1456 lbs. Round your answer to four decimal places.

Find the area under the standard normal curve between z=−2.11 and z=−0.42. Round your answer to four decimal places, if necessary.

The weights of steers in a herd are distributed normally. The standard deviation is 200 lbs and the mean steer weight is 1400 lbs. Find the probability that the weight of a randomly selected steer is less than 1859 lbs. Round your answer to four decimal places.

Suppose babies born in a large hospital have a mean weight of 3366 grams, and a variance of 244,036. If 118 babies are sampled at random from the hospital, what is the probability that the mean weight of the sample babies would differ from the population mean by more than 45 grams? Round your answer to four decimal places.

The electric cooperative needs to know the mean household usage of electricity by its non-commercial customers in kWh per day. They would like the estimate to have a maximum error of 0.14 kWh. A previous study found that for an average family the standard deviation is 1.9 kWh and the mean is 15.2 kWh per day. If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of electricity? Round your answer up to the next integer.

A biologist examines 6 geological samples for lead concentration. The mean lead concentration for the sample data is 0.714 cc/cubic meter with a standard deviation of 0.0126. Determine the 90% confidence interval for the population mean lead concentration. Assume the population is approximately normal. Step 1 of 2: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places. A biologist examines 6 geological samples for lead concentration. The mean lead concentration for the sample data is 0.714 cc/cubic meter with a standard deviation of 0.0126. Determine the 90% confidence interval for the population mean lead concentration. Assume the population is approximately normal.

Step 2 of 2: Construct the 90% confidence interval. Round your answer to three decimal places. The weights of steers in a herd are distributed normally. The variance is 90,000 and the mean steer weight is 1500 lbs. Find the probability that the weight of a randomly selected steer is between 1859 and 2009 lbs. Round your answer to four decimal places.

Find the area under the standard normal curve to the left of z=−2.53 and to the right of z=−0.58. Round your answer to four decimal places, if necessary.

The diameters of ball bearings are distributed normally. The mean diameter is 96 millimeters and the standard deviation is 6 millimeters. Find the probability that the diameter of a selected bearing is greater than 105 millimeters. Round your answer to four decimal places.

A manager records the repair cost for 4 randomly selected TVs. A sample mean of $88.46 and standard deviation of $17.20 are subsequently computed. Determine the 99% confidence interval for the mean repair cost for the TVs. Assume the population is approximately normal.

Step 1 of 2: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places. A manager records the repair cost for 4 randomly selected TVs. A sample mean of $88.46 and standard deviation of $17.20 are subsequently computed. Determine the 99% confidence interval for the mean repair cost for the TVs. Assume the population is approximately normal.

Step 2 of 2: Construct the 99% confidence interval. Round your answer to two decimal places.

Answer 1