maths sample test

In a random sample of 180 American home owners, it was found that 158 of them personaly attend to their yard or garden duties. Test the hypothesis that more than 80% of the American home owners personally work in their yard or garden at α = 0.01. Use the p -value method. W..

Three different companies produce a particular type of electronic component. Random samples of components are selected from each company. Components are put into actual use until they fail and the life time of the components noted are as shown. At α = 0.10, find the F test..

What sampling method was used by a researcher who divided subjects into two groups according to gender and then selected members from each group for her sample? => cluster or stratified or random or systematic..

A manufacturer found that there were 25 defective units out of the 180 sample units. Find the decimal number which is equivalent to the fraction of the defective units to the total number of sample units. => 0.33 or 0.17 or 0.23 or 0.13..

Women constitute 24% of the science and engineering workforce. In a random sample of 500 science and engineering workforce, what is the probability that the sample has exactly 130 women workforce? => 4.23% or 3.24% or 3.42% or 2.54%..

A company produces chain ring bolts and the pack should contain on an average 10 grams with a standard deviation of 1.3 grams. The mean weight of a sample of 40 packs is observed as 9.4 grams. Find the p -value for the test. Can it be concluded that the company is filling the pa..

A consumer claims that the standard deviation of the quantity of softdrink in a bottle is more than 0.23 oz. The researcher of the company selected a sample of 10 bottles and found the standard deviation as 0.32 oz. Find the P -value for the test. At α = 0.05, is there eno..

A company claims that the standard deviation of the gear speed for a piece of machinery is 28 revolutions per minute (rpm). An engineer selected a random sample of 20 machines and found the standard deviation as 40 (rpm). At α = 0.01, is there enough evidence to reject the company's..

In a statistical hypothesis testing, the standard deviation of the population is 8, H 0 : μ ≤ 100 and H 1 : μ > 100. Which of the following is true for the sample mean ( X ‾ ) to reject the null hypothesis(H 0 ) at α = 0.01 for a sample size o..

Assume that the weights of 3,000 students at a university are normally distributed with mean 150 pounds and a standard deviation of 7 pounds. If 100 samples of 30 students each are obtained, then what would be the expected mean and standard deviation of the resulting sampling di..