manufacturer states that the assembly time of a certain component is 3 hours. The population standard deviation for the assembly time of such components is 15 minutes. Fifty components are selected, and the average assembly time is found to be 3.1 hours. Test the manufacturer's claim using a level of significance of 0.05.   a- STEP 1               H0:                                     H1:                          b- STEP 2              α =                           c- STEP 3 Compute the relevant test statistic.                Test Statistics:    d- STEP 4  State the Rejection Criteria. Draw a picture.    e- STEP 5  Decision Regarding H0, state as a complete sentence

A study was done using a treatment group and a placebo group. The results are shown in the table. Assume that the two samples are independent simple random samples selected from normally distributed​ populations, and do not assume that the population standard deviations are equal. Complete parts​ (a) and​ (b) below. Use a 0.05 significance level for both parts.     Treatment Placebo   μ μ1 μ2 n 27 39 x 2.38 2.65 s 0.87 0.61 a. Test the claim that the two samples are from populations with the same mean.   What are the null and alternative​ hypotheses?     A. H0​: μ1≠μ2 H1​: μ1<μ2   B. H0​: μ1<μ2 H1​: μ1≥μ2   C. H0​: μ1=μ2 H1​: μ1>μ2   D. H0​: μ1=μ2 H1​: μ1≠μ2 Your answer is correct. The test​ statistic, t, is   ​(Round to two decimal places as​ needed.)

A population has a mean μ=40 and a standard deviation σ=4. What is the standard deviation of the sampling distribution of the sample means if the sample size is n=16?

A population has a mean μ=85 and a standard deviation σ=21. Find the mean and standard deviation of a sampling distribution of sample means with sample size n=263.

A manufacturer makes ball bearings that are supposed to have a mean weight of 30 g. A retailer suspects that the mean weight is actually less than 30 g. The mean weight for a random sample of 16 ball bearings is 28.6 g with a standard deviation of 4.4 g. Assume the population standard deviation is not known. How many populations? O2 01 What is the parameter? O Proportion О Мean O Variance O tandard Deviation O Difference between Means