Two college instructors are interested in whether or not there is any variation in the way they grade math exams. They each grade the same set of 10 exams. The first instructor's grades have a variance of 33.38. The second instructor's grades have a variance of 88.36. What is the Critical value at 90% confidence level to test the Null Hypothesis H0: σ12 ≥ σ22 against the alternative Ha: σ12 < σ2 2 ?

Two college instructors are interested in whether or not there is any variation in the way they grade math exams. They each grade the same set of 10 exams. The first instructor's grades have a variance of 33.38. The second instructor's grades have a variance of 88.36. What is the Critical value at 90% confidence level to test the Null Hypothesis H0: σ12 ≥ σ22 against the alternative Ha: σ12 < σ2 2 ?

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

A researcher obtains t(20) = 2.00 and MD = 9 for a repeated-measures study. If the researcher measures effect size using the percentage of variance accounted for, what value will be obtained for r2?
An independent-measures study has M1 = 45 and M2 = 49 with a pooled variance of s2p = 4. For this study, Cohen’s d should be reported as = -2.00. True False
To evaluate the effect of a treatment, a sample is ob- tained from a population with a mean of u= 40, and the treatment is administered to the individuals in the sample. After treatment, the sample mean is found to be M =44.5 with a variance of s2 = 36. If the sample consists of n = 4 individuals, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with a = .05? b. If the sample consists of n = 16 individuals, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with a = .05? c. Comparing your answers for parts a and b, how does the size of the sample influence the outcome of a hypothesis test?
An engineer is comparing voltages for two types of batteries (K and Q) using a sample of 7070 type K batteries and a sample of 8585 type Q batteries. The type K batteries have a mean voltage of 8.848.84, and the population standard deviation is known to be 0.3030.303. The type Q batteries have a mean voltage of 9.059.05, and the population standard deviation is known to be 0.3670.367. Conduct a hypothesis test for the conjecture that the mean voltage for these two types of batteries is different. Let μ1μ1 be the true mean voltage for type K batteries and μ2μ2 be the true mean voltage for type Q batteries. Use a 0.010.01 level of significance. Step 1 of 4 : State the null and alternative hypotheses for the test.
An engineer is comparing voltages for two types of batteries (K and Q) using a sample of 7070 type K batteries and a sample of 8585 type Q batteries. The type K batteries have a mean voltage of 8.848.84, and the population standard deviation is known to be 0.3030.303. The type Q batteries have a mean voltage of 9.059.05, and the population standard deviation is known to be 0.3670.367. Conduct a hypothesis test for the conjecture that the mean voltage for these two types of batteries is different. Let μ1μ1 be the true mean voltage for type K batteries and μ2μ2 be the true mean voltage for type Q batteries. Use a 0.010.01 level of significance. Step 3 of 4 : Determine the decision rule for rejecting the null hypothesis H0H0. Round the numerical portion of your answer to three decimal places.
A manufacturer of potato chips would like to know whether its bag filling machine works correctly at the 445 gram setting. Based on a 29 bag sample where the mean is 438 grams and the variance is 676, is there sufficient evidence at the 0.1 level that the bags are underfilled or overfilled? Assume the population distribution is approximately normal. Step 1 of 5 : State the null and alternative hypotheses.
A researcher first decided to conduct a two-tailed hypothesis test, with alpha = .05, but then decided she wants to reduce the risk of a Type I error. What should she do? a. Calculate her statistics more carefully. b. Decrease alpha to .01 c. Increase alpha to .15 e. Conduct a three-tailed test
A juice factory buys apple concentrate from two different suppliers. The mean concentration is the same for both suppliers, but it is suspected that the variability of the concentration could be different for the two suppliers. The standard deviation of the concentration in a random sample of n1 = 12 lots produced by Supplier 1 is s1 = 6.4 g / L, and for Supplier 2, n2 = s2 = 4.8 g / L in a random sample of 12 lots. Is there sufficient evidence to conclude that the variance of the two populations is different by calculating the appropriate test statistic? (α = 0.05)
An engineer asserts that Battery A outperforms Battery B in terms of overall performance. Type A and type B batteries were randomly selected for testing, and the sample means and standard deviations of their voltages were computed in the following ways: Type of battery sample size mean standard deviation Type A 27 9.2V 0.3 V Type B 28 8.8V 0.1 V Assume that the samples are drawn from populations with normal distribution and unequal variances. i. Test the hypothesis at 5% significant level and state the conclusions you can draw.ii. Find the P-value of this test.
A researcher administers a treatment to a sample from a population with a mean of m=50. If the treatment is expected to increase scores and a one-tailed test is used to evaluate the treatment effect, the the null hypothesis states that m=40. True or false?
Random samples from two normal populations produced the following statistics: s2^2=32, n1=10 , n2=15 and s2^2 , Is there enough evidence at the 5% significance level to infer that the variance of Population 1 is larger than the variance of Population 2? The null and alternative hypotheses is: