Question

In: Statistics and Probability

An investigator compares the durability of two different compounds used in the manufacture of a certain...

An investigator compares the durability of two different compounds used in the manufacture of a certain automobile brake lining. A sample of 256 brakes using Compound 1 yields an average brake life of 49,386 miles. A sample of 298 brakes using Compound 2 yields an average brake life of 47,480 miles. Assume that the population standard deviation for Compound 1 is 1649 miles, while the population standard deviation for Compound 2 is 3911 miles. Determine the 95% confidence interval for the true difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2.

Step 1 of 3 : Find the point estimate for the true difference between the population means.

Step 2 of 3: Calculate the margin of error of a confidence interval for the difference between the two population means. Round your answer to sox decimal places.

Step 3 of 3: Construct the 80% confidence interval. Round your answers to the nearest whole number.

Solutions

Expert Solution


Detailed solution is provided below
Note :We use zstatistic since the population standard deviation is provided and the sample size is more than 30

95% confidence interval


80% confidence interval


Related Solutions

An investigator compares the durability of two different compounds used in the manufacture of a certain...
An investigator compares the durability of two different compounds used in the manufacture of a certain automobile brake lining. A sample of 65 brakes using Compound 1 yields an average brake life of 37,409 miles. A sample of 31 brakes using Compound 2 yields an average brake life of 49,036 miles. Assume the standard deviation of brake life is known to be 1341 miles for brakes made with Compound 1 and 2961 miles for brakes made with Compound 2.  Determine the...
An investigator compares the durability of two different compounds used in the manufacture of a certain...
An investigator compares the durability of two different compounds used in the manufacture of a certain automobile brake lining. A sample of 125 brakes using Compound 1 yields an average brake life of 41,759 miles. A sample of 163 brakes using Compound 2 yields an average brake life of 40,361 miles. Assume that the population standard deviation for Compound 1 is 3921 miles, while the population standard deviation for Compound 2 is 3097miles. Determine the 95% confidence interval for the...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that are designed to reduce braking distances for SUVs equipped with the tires. SUVs equipped with tires using compound 1 have a mean braking distance of 7272 feet and a standard deviation of 11.811.8 feet. SUVs equipped with tires using compound 2 have a mean braking distance of 7575 feet and a standard deviation of 11.311.3 feet. Suppose that a sample of 5757 braking tests...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that are designed to reduce braking distances for SUVs equipped with the tires. SUVs equipped with tires using compound 1 have a mean braking distance of 76 feet and a standard deviation of 8.9 feet. SUVs equipped with tires using compound 2 have a mean braking distance of 80 feet and a standard deviation of 14.6 feet. Suppose that a sample of 45 braking tests...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that are designed to reduce braking distances for SUVs equipped with the tires. SUVs equipped with tires using compound 1 have a mean braking distance of 62 feet and a standard deviation of 10.6 feet. SUVs equipped with tires using compound 2 have a mean braking distance of 68 feet and a standard deviation of 13.9 feet. Suppose that a sample of 77 braking tests...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that are designed to reduce braking distances for SUVs equipped with the tires. SUVs equipped with tires using compound 1 have a mean braking distance of 62 feet and a standard deviation of 10.5 feet. SUVs equipped with tires using compound 2 have a mean braking distance of 66 feet and a standard deviation of 12.0 feet. Suppose that a sample of 86 braking tests...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that are designed to reduce braking distances for SUVs equipped with the tires. SUVs equipped with tires using compound 1 have a mean braking distance of 45 feet and a standard deviation of 11.6 feet. SUVs equipped with tires using compound 2 have a mean braking distance of 49 feet and a standard deviation of 6.1 feet. Suppose that a sample of 76 braking tests...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that are designed to reduce braking distances for SUVs equipped with the tires. The mean braking distance for SUVs equipped with tires made with compound 1 is 6969 feet, with a population standard deviation of 10.910.9. The mean braking distance for SUVs equipped with tires made with compound 2 is 7777 feet, with a population standard deviation of 14.814.8. Suppose that a sample of 3434...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that are designed to reduce braking distances for SUVs equipped with the tires. The mean braking distance for SUVs equipped with tires made with compound 1 is 74 feet, with a population standard deviation of 13.4. The mean braking distance for SUVs equipped with tires made with compound 2 is 77 feet, with a population standard deviation of 14.3. Suppose that a sample of 41...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that...
A researcher compares two compounds (1 and 2) used in the manufacture of car tires that are designed to reduce braking distances for SUVs equipped with the tires. SUVs equipped with tires using compound 1 have a mean braking distance of 76 feet and a standard deviation of 8.9 feet. SUVs equipped with tires using compound 2 have a mean braking distance of 80 feet and a standard deviation of 14.6 feet. Suppose that a sample of 45 braking tests...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT