Statistics and Probability Answers

A group of four IC chips consists of two good chips and two defective chips. The experiment consists of selecting three chips at random from this group. Write the sample space of the possible outcomes. What is the probability that two are defective?

A population of Grade 11 Arts and Design Students of size N=140 has mean grade of u=83 in Arts Subject and a population standard deviation of 25.

1.) What is the z-score of the the sample mean 80 if the sample size n=30?

2.) What is the area or probability of the sample mean 75 of the sample size n=30?

3.) What is the area greater than the sample mean of 80 if the sample size n=30?

A garment factory distributes two brands of jeans. If it is found that 75 out of 250 customers prefer brand A and that 30 out of 150 prefer brand B, can we conclude at 0.05 level of significance that brand A outsells brand B?

a. State the null and alternative hypothesis

b. Determine the significance level

c. Select the test statistic to be used

d. Compute the test statistic value

e. Determine the critical value

f. Sketch the rejection region

g. Draw the conclusion

A SHS student conducted a survey to test the claim that "less than half of all the adults are annoyed by the violence on television". Suppose that from a poll of 2,400 surveyed adults, 1,152 indicated their annoyance with television violence. Test this claim using 0.10 level of significance

a. State the null and alternative hypothesis

b. Determine the significance level

c. Select the test statistic to be used

d. Compute the test statistic value

e. Determine the critical value

f. Sketch the rejection region

g. Draw the conclusion

manufacturer does not know the mean and SD of the diameters of ball bearings he is 

producing. However, a sieve system rejects all bearings larger than 2.4cm and those under 

1.8cm in diameter. Out of 1000 ball bearings 8% are rejected as too small and 5.5% as too 

big. What is the mean and standard deviation of the ball bearings produced assuming that 

the diameters of ball bearings are normally distributed?

The Guidance Counselor of your school claims that the Grade 11 students spend an average of 11.28 hours in a week doing performance tasks with standard deviation of 1.64. Your adviser thinks that students spend more time in doing performance tasks, so he decided to conduct his own research. He used a sample of 46 Grade 11 students and obtained a mean of 11.83. Is there enough evidence at 0.05 level of significance that the students spend 11.28 hours in a week doing performance tasks?

Consider a population consisting of 2.3.4 and 6 illustrate the situation by doing the following:

1.Compute the mean and variance of the population

2.list all possible samples of size 2

3.construct the sampling distribution of the sample

4. Compute the mean and standard deviation of the sampling distribution of the sample means

5.construct the histogram.

A population consists of the numbers of 1-5.List all the possible samples of size 3 from this population and construct the sampling distribution of the sample mean.

A population consists of the numbers of 1-5.List all the possible samples of size 3 from this population and construct the sampling distribution of the sample mean.