sample test

A company reported that 95% of the batteries manufactured by it would provide back up support for 50 hours continuously. In a random sample of 120 batteries, 113 supported 50 hours continuously. Find the test value at α = 0.01. Is there enough evidence to reject the compan..

A sample of 150 people out of 240 from an industrial community and 60 out of 90 people from a rural communtiy suffered from a lung disease. At 90% confidence level, find the test value and verify if their proportions differ significantly. => 0.708, the proportions do not differ ..

A survey reported that 12.6% of all working women earned between $5.15 and $6.14 per hour in 1998. From a random sample of 140 working women, it was found that 20 are in such category. Test the survey report at α = 0.01. => z = 0.303, not enough evidence to reject the repo..

In a statistical hypothesis test, s 2 is the sample variance, s 2 the population variance and n the sample size, than the formula for the chi-square test for a single variance is: => n s 2 σ 2 or ( n - 1 ) s 2 σ 2 or ( n - 1 ) σ 2 s 2 or ( n..

A standard notebook is supposed to have on an average, 200 pages, with a standard deviation of 2 pages. From a supply of 2500 notebooks, a random sample of 40 notebooks was taken and found that the mean number of pages in the notebook was 197. Test at the 0.05 level of confidenc..

Two laboratories carried out tests on five samples of ice cream to find out the fat content in it. What did the results show at 95% and 99% confidence levels? Lab A 7 9 8 10 8 Lab B 9 8 8 9 7 => do not differ at 95% and at 99% or do not differ at 95% and differ at 99% or differ ..

Choose the incorrect statement(s). I. A statistic is a numeric descriptive measure of a population. II. The sampling error is the difference between the population value of interest and sample value. III. If the sample is randomly selected from the population, then ..

The report of a municipal corporation states that the average monthly electricity bill of a household in the city is more than $73. To test this report, a researcher selected a sample of 100 residential electricity bills and found the mean as $74.50 with a standard deviation as ..

The amount of magazine sales (in million dollars) for a sample of 7 years are 2.6, 1.8, 2.0, 3.2, 1.6, 3.4, 2.3. Find the sample variance and sample standard deviation. => 1.066 and 1.136 or 0.475 and 0.689 or 1.136 and 1.066 or 2.113 and 1.45..

Which of the following are the assumptions for two-way ANOVA? I. All samples are drawn from normally distributed populations. II. All populations have a common variance. III. The groups must be equal in sample size. IV. Within each group, the observations were sampled ..