Question

A certain type of stainless steel powder is supposed to have a mean particle diameter of...

A certain type of stainless steel powder is supposed to have a mean particle diameter of 15 microns. A random sample of 50 particles had a mean diameter of 15.2 microns. If the population standard deviation is 0.6 microns, is there any evidence to suggest that the population has a mean diameter of 15 microns? Assume ? = 0.05.

a. Use P-value method to test the hypothesis.

b. Clearly write your conclusion.

c. If the true mean diameter is 15.2 microns, what is the type II error?

d. If the true mean diameter is 15.2 microns, what should be the minimum sample size needed to recognize it with 99% probability.

Homework Answers

Answer #1

Given that sample size =n= 50

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A certain type of stainless steel powder is supposed to have a mean particle diameter of...
A certain type of stainless steel powder is supposed to have a mean particle diameter of μ = 15 μm. A random sample of 86 particles had a mean diameter of 15.2 μm, with a standard deviation of 1.8 μm. A test is made of H0 : μ = 15 versus H1 : μ ≠ 15. Find the P-value. Round the answer to four decimal places. Numeric Response
Type I error: Washers used in a certain application are supposed to have a thickness of...
Type I error: Washers used in a certain application are supposed to have a thickness of 2 millimeters. A quality control engineer measures the thicknesses for a sample of washers and tests H0: μ = 2 versus H1: μ ≠ 2. b. If a Type II error is made, what conclusion will be drawn regarding the mean washer thickness?
The diameters of steel shafts produced by a certain manufacturing process should have a mean diameter...
The diameters of steel shafts produced by a certain manufacturing process should have a mean diameter of 5.5 inches. The diameter is known to have a standard deviation of 0.9 inches. A random sample of 30 shafts. (a) Find a 90% confidence interval for the mean diameter to process. (b) Find a 99% confidence interval for the mean diameter to process. (c) How does the increasing and decreasing of the significance level affect the confidence interval? Why? Please explain and...
The diameter of steel rods manufactured on two different extrusion machines is being investigated. Two random...
The diameter of steel rods manufactured on two different extrusion machines is being investigated. Two random samples of sizes ?1 = 20 and ?2 = 24 are selected, and the sample means and sample variances are ?̅̅1̅ = 9.22, ?1 = 0.55, ?̅̅2̅ = 9.43, and ?2 = 0.62, respectively. Assume that ?1 2 = ?2 2 and that the data are drawn from a normal distribution. Is there evidence to support the claim that the two machines produce rods...
In a survey of 500 residents in a certain town, 312 said they were opposed to...
In a survey of 500 residents in a certain town, 312 said they were opposed to constructing a new shopping mall. Can you conclude that at least 60% of the residents in this town are opposed to constructing a new shopping mall? Use ? = 0.05. a. Find 95% confidence interval and use it to test the hypothesis. b. Clearly write your conclusion. c. If the true percentage of town residents opposing the new shopping mall is 65%, what is...
IQ: Scores on a certain IQ test are known to have a mean of 100 ....
IQ: Scores on a certain IQ test are known to have a mean of 100 . A random sample of 51 students attend a series of coaching classes before taking the test. Let μ be the population mean IQ score that would occur if every student took the coaching classes. The classes are successful if μ > 100 . A test is made of the hypotheses H0 :μ=100 versus H1 :μ>100. Consider three possible conclusions: (i) The classes are successful....
To obtain information on the corrosion-resistance properties of a certain type of steel conduit, 45 specimens...
To obtain information on the corrosion-resistance properties of a certain type of steel conduit, 45 specimens are buried in soil for a 2-year period. The maximum penetration (in mils) for each specimen is then measured, yielding a sample average penetration of x = 52.3 and a sample standard deviation of s = 4.2. The conduits were manufactured with the specification that true average penetration be at most 50 mils. They will be used unless it can be demonstrated conclusively that...
To obtain information on the corrosion-resistance properties of a certain type of steel conduit, 45 specimens...
To obtain information on the corrosion-resistance properties of a certain type of steel conduit, 45 specimens are buried in soil for a 2-year period. The maximum penetration (in mils) for each specimen is then measured, yielding a sample average penetration of x = 53.2 and a sample standard deviation of s = 4.2. The conduits were manufactured with the specification that true average penetration be at most 50 mils. They will be used unless it can be demonstrated conclusively that...
IQ scores follow a Normal distribution with a mean μ = 100 and standard deviation σ...
IQ scores follow a Normal distribution with a mean μ = 100 and standard deviation σ = 15. A SRS of 31 seventh-grade girls in one school district is tested and the sample mean x¯¯¯x¯ was = 102 . Is there evidence that the mean IQ score in this district is different from from 100? The alternative hypothesis is: Ha: u < 100 Ha: u > 100 Ha: u ≠ 100 The test statistic, z =....... (+ 0.01) P(z )...
1. Find the area under the standard normal curve (round to four decimal places) a. To...
1. Find the area under the standard normal curve (round to four decimal places) a. To the left of  z=1.65 b. To the right of z = 0.54 c. Between z = -2.05 and z = 1.05 2. Find the z-score that has an area of 0.23 to its right. 3. The average height of a certain group of children is 49 inches with a standard deviation of 3 inches. If the heights are normally distributed, find the probability that a...