customers. The appropriate null hypothesis for this situation is: H0: μ = 31.7 H0:  = 31.7     H0: μ = 32 H0:  = 32 The appropriate alternative hypothesis for this situation is: Ha: μ > 31.7

An electronics production sequence includes a process where a film of metal is deposited on a board. The film must be more than 1.000 mm thick. If the film is too thin the process fails. The engineer ran a test where the null hypothesis was that the mean thickness was at most 1.000 mm. A sample of 100 boards had a mean thickness of 1.007 mm and a standard deviation of 0.050 mm.At what level of significance would the null hypothesis be rejected? Express your answer at a decimal (not a percent) rounded to three places.

purses Researchers conducted an experiment to test the effects of alcohol. Erors were recorded in a test of visual and motor skills for a treatment group of 21 people who drank ethanol and another group of 21 people given a placebo. The errors for the treatment group have a standard deviation of 2.10, and the errors for the placebo group have a standard deviation of 0.71. Use a 0.05 significance level to test the claim that the treatment group has errors that vary significantly more than the errors of the placebo group. Assume that the two populations are normally distributed. se Hom bus What are the null and alternative hypotheses? ndar O A. Ho: o =0 O B. Ho: of +o? ntation OC. Ho o =0 OD. Hoi o? =o} book puncem Identify the test statistic. (Round to two decimal places as needed.) gnments Use technology to identify the P-value. dy Plan (Round to three decimal places as needed.) debook What is the conclusion for this hypothesis test? O A. Reject Ho. There is sufficient evidence to…

Americans are about 1 inch taller but nearly 25 pounds heavier than in 1960. The average BMI increased from approximately 25 to 28 in 2002. Boston is considered one of americas healthiest cities. Is the weight gain since 1960 similar in boston? Sample of n=25 and mean increase of 17 with standard deviation of 8.6. Is boston statistically significantly different in terms of weight gain since 1960? Run the appropriate test at 5%level of significance.  A.state the null and the research hypotheses, b. Idebtify critical values of z 9r t used to define the decision rule, c. Calculate the test statistic, d. Report the p-value, e. Report your findings

The void volume within a textile fabric affects comfort, flammability, and insulation properties. Permeability of a fabric refers to the accessibility of void space to the flow of a gas or liquid. An article gave summary information on air permeability (cm3/cm2/sec) for a number of different fabric types. Consider the following data on two different types of plain-weave fabric: Fabric Type Sample Size Sample Mean Sample Standard Deviation Cotton 10 51.41     0.75 Triacetate 10 132.15     3.59 Assuming that the porosity distributions for both types of fabric are normal, let's calculate a confidence interval for the difference between true average porosity for the cotton fabric and that for the acetate fabric, using a 95% confidence level. Before the appropriate t critical value can be selected, df must be determined: df =    0.5625 10  +  12.8881 10   2   (0.5625/10)2 9  +  (12.8881/10)2 9  =  1.8092 0.1849…

Community college instructors' salaries in one state are very low, so low that educators in that state regularly complain about their compensation. The national mean is $⁢60,156, but instructors from Mississippi claim that the mean in their state is significantly lower. They survey a simple random sample of 33 colleges in the state and calculate a mean salary of $⁢56,842 with a standard deviation of $⁢10,813. Test the instructors' claim at the 0.10 level of significance Step 1 of 3: State the null and alternative hypotheses for the test. Step 2 of 3: Compute the value of the test statistic. Round your answer to three decimal places. Step 3 of 3: Draw a conclusion and interpret the decision

Do political science classes require the same amount of writing as history classes? The 47 randomly selected political science classes assigned an average of 14.5 pages of essay writing for the course. The standard deviation for these 47 classes was 4 pages. The 41 randomly selected history classes assigned an average of 16.7 pages of essay writing for the course. The standard deviation for these 41 classes was 3.6 pages. What can be concluded at the αα = 0.01 level of significance? For this study, we should use        The null and alternative hypotheses would be:        H0:H0:     Correct      Correct    Correct       H1:H1:     Correct      Correct    Correct The test statistic     =  (please show your answer to 3 decimal places.) The p-value =  (Please show your answer to 4 decimal places.) The p-value is     αα Based on this, we should      the null hypothesis. Thus, the final conclusion is that ... The results are statistically significant at αα = 0.01, so there is sufficient…

Community college instructors' salaries in one state are very low, so low that educators in that state regularly complain about their compensation. The national mean is $59,739 , but instructors from Mississippi claim that the mean in their state is significantly lower. They survey a simple random sample of 46 colleges in the state and calculate a mean salary of $55,618 with a standard deviation of $10,891 . Test the instructors' claim at the 0.10 level of significance. Step 2 of 3 : Compute the value of the test statistic. Round your answer to three decimal places.