Statistics and Probability Answers

Assuming that you have 50 subjects that you want to randomly assign to two different groups of 25, explain how you would use a random number table to do it.

In trying to evaluate the effectiveness of its advertising campaign, a firm completed the following information:
Year : 1 2 3 4 5 6 7 8
Advertising Expenditure (000) : 12 15 15 23 24 38 42 48
Sales (00000) : 5.0 5.6 5.8 7.0 7.2 8.8 9.2 9.5
i) Is the advertising expenditure and sales of this firm related?
ii) Given an advertising expenditures of 60,000, what will the sales turn out to be?
iii) Calculate the 3 yearly moving average of the sales.
iv) Find the mean and standard deviation of a normal distribution when 8% of the items are over 64 and 31% are under 45.

Many U.S. households still do not have Internet access. Suppose 25 out of 80 households in a small southern town do not have Internet access. A company that provides high-speed Internet has recently entered the market. As part of the marketing campaign, the company decides to randomly select ten households and offer them red laptops along with a brochure that describes their services. The aim is to build goodwill and, with a free laptop, tempt nonusers into getting Internet access.
a. What is the probability that six laptop recipients do not have Internet access?
(2 Marks)
b. What is the probability that at least five recipients do not have Internet access?
(2 Marks)
c. What is the probability that two or fewer laptop recipients do not have Internet access?
(2 Marks)
d. What is the expected number of laptop recipients who do not have Internet access?
(1 Marks)
e. Calculate the expected value, the variance, and the standard deviation for the recipients who do not have Internet access.

The CEO of Games4U wants company employees to be happy at work. The results of a survey showed that the mean happiness score of all company employees was normally distributed with a mean of 13.10 and a standard deviation of 1.95. (scale 1 to 20) a. If an employee is randomly selected, what is the probability that his score is less than 11.50? b. If 10 employees are randomly selected, what is the probability that their scores are less than 11.50? Why is the small sample size in (b) not a problem? C. Why is the small sample size in (b) not the problem?

Specify the null hypothesis (Ho) and the alternative hypothesis (Ha).

5) In an experimental group of 250 individuals, half were given regular doses of aspirin while the other half were given placebos with no effects. Test the claim that the aspirin group has a significantly lower heart attack rate than the placebo group.

6) Is there a significant difference in the level of practice of accountants in terms of type of corporation (private-owned or government-owned)?

7) Are there differences in the degree of influence encountered by the employees when grouped according to status of appointment (contractual or permanent)?

Specify the null hypothesis (Ho) and the alternative hypothesis (Ha).

1) A researcher wants to determine if the mean monthly household expenditure is really P12,760 as published.

2) A health practitioner wants to know in the mean weight of girls at birth is at least 3.2 kg as per record of a particular hospital.

3) A producer of steel cables wants to test if the steel cables it produces have a breaking strength of 450 lb.

4) The DTI receives many complaints from consumers that the bottles of cooking oil sold by a company contain less than the 1 liter of oil advertised.

specify the null hypothesis (Ho) and the alternative hypothesis (Ha).

1) A researcher wants to determine if the mean monthly household expenditure is really P12,760 as published.
2) A health practitioner wants to know in the mean weight of girls at birth is at least 3.2 kg as per record of a particular hospital.
3) A producer of steel cables wants to test if the steel cables it produces have a breaking strength of 450 lb.
4) The DTI receives many complaints from consumers that the bottles of cooking oil sold by a company contain less than the 1 liter of oil advertised.