Statistics and Probability Answers

A survey of 300 Senior High School learners shows that they read on average of 20 hours per week with a margin of error of 2.2 hours at 95% level of confidence.

21. What is the sample mean? A. 20 B. 300 C. 2.2 D. 0.05

22. Which of the following is the upper limit of the interval? A. 15 B. 17.8 C. 22.2 D. 1.96

23. What is the lower limit of the confidence interval? A. 17.8 B. 1.96 C. 22.2 D. 4.4

24. What is the length of the confidence interval? A. 17.8 B. 22.2 C. 4.4 D. 2.

If the variance of the population is 5, what is the variance of the sampling distribution of the means of size 3 drawn from this population?

A sample of 160 people has a mean age of 27 with a population standard deviation of 5. Test the hypothesis that the population mean is 26.7 at =0.05

the average cholesterol of a certain canned goods is 180 milligrams, and the standard deviation is 12 milligrams. assume that the variable is normally distributed. if a sample of 16 canned goods is selected, what is the probability that the mean of the sample will be greater than 172 milligrams

the average number of pages in a novel is 276 witha standard deviation of 18 pages. is a sample of 40 novels is randomly chosen, what is the probability that the average number of pages in these books is between 268 and 281?

Assume that the variable is normally distributed, the average time it takes a group of senior high school sidents to complete a certain examination is 40.2 minutes while the standard deviation is 8 minutes

What is the probability that a randomly selected senior high school students will complete the examination in less than 43 minutes? the given altuation, what words would give us a clue to the direction of the

curve or where the shaded part is located?

assuming that the sample come from the normal distributions find the margim of error. E given the following

B.n=16,X =50, s=4.2, 95% confidence

The leader of the association of jeepney drivers claims that the average daily take home pay of all jeepney drivers in a particular city is php 450. A random sample of 100 jeepney drivers in the city was interviewed and the average daily take home pay of these drivers is found to be php 500. Use a 0.05 significance level to find out if the average daily take home pay of all jeepney drivers in the city is greater than php 450. Assume that the population variance is php 8644.

The diameters of washers are normally distributed with mean 50mm and variance

4mm. A washer is considered non-defective if its diameter lies between 46mm and

53mm. If one washer is randomly selected, what is the probability that:

4.2.1 its diameter less than 45mm? (6)

4.2.2 itis defective?

There is a claim that on daily average students spend 5.5 hours on social media with standard deviation of 1.25 .A resercher wants to test the claim at 5% level significance.

1.formulate the null and alternatuve hyphothesis

2.Determine the test statistic to be used

3.Find the corresponding z value

4. Identify the rejection region