random samples

The average annual temperature of a place is 68°F and the standard deviation is 10°F. If a random sample of 36 days is taken, then find the probability that the mean sample temperature is less than 70°F? => 89.62% or 39.62% or 10.38% or 60.38%..

Which of the following statement(s) refers to a population? I. A sample of 50 bags of potatoes from a lot. II. The number of children in a city. III. A random sample of 100 policy holders. IV. The average percapita income of the people in a state. => III only or I and ..

A survey reported that 70% of college students aged 18 to 26 own a cell phone. To test this report a professor selected a random sample of 150 college students and found that 100 own a cell phone. Is the sample report differs from population report at α = 0.05? W..

Select the incorrect statement(s). I. A sampling distribution of sample means is a distribution obtained by using the means computed from random samples of a specific size taken from a population. II. Sampling error is the difference between the ..

A soft drink company claims that the mean quantity of soft drink in a tin is 300 ml with a standard deviation of 5 ml. A random sample of 65 bottles from a shipment had a mean of 296.5 ml. Is the shipment is significantly different from the standard at the 0.05 level of signific..

A retail garment shop receives a shipment of trousers, with a standard length of 49.0 in. and a standard deviation of 1.0 inch. A random sample of 32 trousers had a mean length of 48.8 in. Which of the following statements is true? => The sample mean does not lie with ..

Radio tubes manufactured by a company are expected to have a mean lifetime of 400 hours, with a standard deviation of 30 hours. Random samples of 10 tubes were tested. It was found that 3 tubes had a lifetime of 398 hours, 5 of them had a lifetime of 410 hours and 2 had a lifeti..

A retail garment shop receives a shipment of trousers, with a standard length of 49.0 in. and a standard deviation of 1.0 inch. A random sample of 32 trousers had a mean length of 48.8 in. Find the 95% confidence interval. => The interval between 48.65 and 49.35 or The interval ..

Which of the following are the assumptions needed for the goodness-of-fit test? I. The data are obtained from a random sample. II.The expected frequency for each category must be 5 or more. III.The expected frequency for each category must be less than 5. => II and III only or I..

A random sample of the number of schools in various regions is shown. At α = 0.10, find the F test value and test the claim that the mean number of schools are the same. => 2.7, not the same or 3.84, the same or 3.84, not the same or 2.7, the same..