Search & Filtering
full time students, the outcomes were recorded according to the following table ]
19 28 27 32 37 41 42 24
Calculate a point estimate and also estimate a 95% confidence interval for
the mean number of days absent for the students.
Note: t-limits 2.365
have been many shortages from the cash register lately. There is only one employee who could have
taken money from the register during these periods. Realizing that the shortages might have
resulted from the employee inadvertently giving incorrect change to customers, the employer does
not know whether to forget the situation or accuse the employee of theft. In words, what are the
null and alternative hypotheses? Explain your choices
3.5 How would your answers to (3.4) if you were looking at the problem from the internet provider’s
point of view and wanted to prove to potential customers that your system was good?
The manager at Costello Drug Store assumes the company’s employees are honest. However, there have been many shortages from the cash register lately. There is only one employee who could have taken money from the register during these periods. Realizing that the shortages might have resulted from the employee inadvertently giving incorrect change to customers, the employer does not know whether to forget the situation or accuse the employee of theft. In words, what are the null and alternative hypotheses? Explain your choices
.4 The system is tested on a sample of one hundred computers and the average connection speed is found to be far below 400 kilobits. What hypothesis should probably be rejected? Explain. If the customer needs a connection speed of 400 kilobits to run her application programs, what is the business decision that corresponds to the decision regarding the hypotheses?
have been many shortages from the cash register lately. There is only one employee who could have
taken money from the register during these periods. Realizing that the shortages might have
resulted from the employee inadvertently giving incorrect change to customers, the employer does
not know whether to forget the situation or accuse the employee of theft. In words, what are the
null and alternative hypotheses? Explain your choices.
3.1 What constitutes a Type 1 error (10)
3.2 What is a Type II error? Which do you think is more serious? Explain. (5)
3.3 A new internet provider claims that using their system you can get transmission speeds of 400
kilobits per second. Specify, both statistically and in English, the null and alternative hypotheses a
potential customer should investigate if she is worried that the connection is really slower than
advertised. Explain your reasoning. (5)
Suppose that the companies A, B, C produce Laptops. Company A produces twice as many as B ; while B and C produce the same number. It is known that 2% of A, 2% of B and 4% of C are defective. All the Laptops produced are put into one shop, and then one Laptop is selected randomly. (i) Determine the probability that the Laptop is defective. (ii) Suppose the Laptop chosen is defective, what is the probability that Laptop is produced by company B.
states that the drug is equally effective for men and women. To test this claim, they choose a
simple random sample of 100 women and 200 men from a population of 100,000 volunteers.
At the end of the study, 38% of the women caught a cold; and 51% of the men caught a cold.
Based on these findings, can we reject the company's claim that the drug is equally effective for
men and women? Use a 0.05 level of significance.
in the mathematics ability of freshmen. Using this grant money, he is able to obtain larger samples.
The results are compiled in the following table.
Last year
This year
Size of sample
125
100
Average score
562
568
Standard deviation
40
42
Can the professor reject the null hypothesis that the average scores improved? Use a 5 % level of
significance.
2.2 In a recent poll, 800 voters were randomly sampled and asked whether they would approve of
the building of an incinerator in the state. According to the poll, 450 voters approved and 350
voters disapproved. Is there enough evidence to argue that more than 50 % of the voters support
the building of the incinerator?
Use a 5 % level of significance.
2 men M1 and M2 and 3 women W1, W2 and W3 are trying for promotion in a firm to a single post which is vacant. Those of the same sex have equal probabilities of getting promotion but each man is twice as likely to get the promotion as any woman.
1.) Find the probability that woman gets the promotion
2.) If M2 and W2 are couple, find the probability that one of them gets the promotion
instructional approaches, all of which are concerned with developing a specified level of skill
in computer-assisted design. The achievement test scores at the conclusion of the
instructional unit are reported in Table along with the mean performance score associated
with each instructional approach. Use the analysis of variance procedure to test the null
hypothesis that the three-sample means were obtained from the same population, using the
5 percent level of significance for the test.
#340153 on Dec 2023