Lazurus Steel Corporation produces iron rods that are supposed to be inches long. The machine that makes these rods does not produce each rod exactly inches long. The lengths of the rods vary slightly. It is known that when the machine is working properly, the mean length of the rods made on this machine is inches. The standard deviation of the lengths of all rods produced on this machine is always equal to inch. The quality control department takes a sample of such rods every week, calculates the mean length of these rods, and makes a confidence interval for the population mean. If either the upper limit of this confidence interval is greater than inches or the lower limit of this confidence interval is less than inches, the machine is stopped and adjusted. A recent sample of rods produced a mean length of inches. Based on this sample, will you conclude that the machine needs an adjustment? Assume that the lengths of all such rods have a normal distribution. Round your answers to two decimal places. The confidence interval is _ to _inches.
Since you have provided data
I am going to give formula with an example
Assuming sample mean is 36.015
sd = 0.035
n = 20
assuming alpha = 0.05 , z = 1.96
confidence interval is
36<μ<36.03
if alpha = 0.10 , z = 1.645
36.002<μ<36.028
Lazurus Steel Corporation produces iron rods that are supposed to be inches long. The machine that...
Lazarus Steel Corporation produces iron rods that are supposed to be 36 inches long. The machine that makes these rods does not produce each rod exactly 36 inches long. The lengths of the rods are normally distributed, and they vary slightly. It is known that when the machine is working properly, the mean length of the rods is 36 inches. The standard deviation of the lengths of all rods produced on this machine is always equal to .035 inch. The...
9.29 Lazurus Steel Corporation produces iron rods that are supposed to be 36 inches long. The machine that makes these rods does not produce each rod exactly 36 inches long. The lengths of the rods are approximately normally distributed and vary slightly. It is known that when the machine is working properly, the mean length of the rods is 36 inches. The standard deviation of the lengths of all rods produced on this machine is always equal to.035 inch. The...
A steel factory produces iron rods that are supposed to be 36 inches long. The machine that makes these rods does not produce each rod exactly 36 inches long. The lengths of these rods vary slightly. It is known that when the machine is working properly, the mean length of the rods is 36 inches. According to design, the standard deviation of the lengths of all rods produced on this machine is always equal to .05 inches. The quality control...
A steel factory produces iron rods that are supposed to be 36 inches long. The machine that makes these rods does not produce each rod exactly 36 inches long. The lengths of these rods vary slightly. It is known that when the machine is working properly, the mean length of the rods is 36 inches. According to design, the standard deviation of the lengths of all rods produced on this machine is always equal to .05 inches. The quality control...
A machine at Katz Steel Corporation makes 3-inch-long nails. The probability distribution of the lengths of these nails is approximately normal with a mean of 3 inches and a standard deviation of 0.12 inch. The quality control inspector takes a sample of 25 nails once a week and calculates the mean length of these nails. If the mean of this sample is either less than 2.95 inches or greater than 3.05 inches, the inspector concludes that the machine needs an...
A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 93.4- cm and a standard deviation of 0.6-cm. Find the proportion of steel rods with lengths between 92 cm and 95.1 cm. Enter your answer as a number accurate to 4 decimal places. A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 155.6-cm and a standard deviation of 2-cm. A steel rod is...
1. A machine produces metal rods used in an automobile suspension system. A random sample of 15 rods is selected, and the diameter is measured. The resulting data (in millimeters) are as follows: 11.44 11.39 11.35 11.38 11.45 11.4311.4211.44 11.34 11.39 11.46 11.36 11.44 11.49 11.41 a) Use a Normal Probability Plot to check the assumption of normality for rod diameter. b) Is it believable the mean rod diameter is less than 1 1.50 mm? Construct the appropriate 99% confidence...
A machine produces metal rods used in an automobile suspension system. A random sample of 15 rods is selected, and the diameter is measured. The resulting data (in millimeters) are as follows: 8.20 8.25 8.18 8.25 8.22 8.20 8.28 8.28 8.18 8.24 8.25 8.25 8.17 8.26 8.22 8-80 Consider the suspension rod diameter measurements described in Exercise 8-40 (use the modified data of 8-40 as given in Chapter 8 homework problems), compute a 99% prediction interval on the diameter of...
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showing work would be helpful! thanks Shulman Steel Corporation makes bearings that are supplied to other companies. One of the machines makes bearings that are supposed to have a diameter of 4 inches. The bearings that have a diameter of either more or less than 4 inches are considered defective and are discarded. When working properly, the machine does not produce more than 10% of bearings that are defective. The quality control inspector selects a sample of 225 bearings each...