Statistics and Probability Answers

The principal of a school claims that 30% of the grade 11 students eat lunch

in school. A survey among 500 grade 11 students revealed that 150 of them

stayed in school during lunch. Use 95% confidence to conduct a test of

proportions.

1.645

z = 3.294

13

Step 1:Statistical

Hypotheses and

Direction of Test

H0 :

H1 :

Statistical Test :

Direction of Test :

Step 2: Level of Significance

and Critical Value

α :

zCV :

Step 3: Test Statistic zTV :

Step 4: Normal curve

Step 5: Findings and

Decision

Step 6: Interpretation

Step 7: Conclusion

The principal of a school claims that 30% of the grade 11 students eat lunch

in school. A survey among 500 grade 11 students revealed that 150 of them

stayed in school during lunch. Use 95% confidence to conduct a test of

proportions.

1.645

z = 3.294

13

Step 1:Statistical

Hypotheses and

Direction of Test

H0 :

H1 :

Statistical Test :

Direction of Test :

Step 2: Level of Significance

and Critical Value

α :

zCV :

Step 3: Test Statistic zTV :

Step 4: Normal curve

Step 5: Findings and

Decision

Step 6: Interpretation

Step 7: Conclusion

A toy company wishes to put a new toy in the market for the Christmas season. It does not want to do so if the manufacturing process produces more than 10% of toys that do no work. In a test run producing 80 of the toys, 10 are found to be defective. Based on the sample evidence, should the company continue to put a new toy in the market? Use 0.05 level of significance.

in a reading ability test, with a sample of 100 cases, the mean score is 40 and

the standard deviation is 4.0. Assuming normality, What is the probability that a score will lie below score 46

The label on a can of pineapple slices that the mean carbohydrate content per serving of canned pineapple is less than 50 grams. It may be assumed that the standard deviation of the carbohydrate content is 4 grams. A random sample of forty servings has a mean carbohydrate content of 52.3 grams. Is the company correct in its claim? Use level of significance 0.05.

suppose there are four people to tested in covid 19. let P represent positive N represent negative and Z represent the number of infected persons that occur.Find the random variable Z

In a plant nursery, the owner thinks that the length of seedlings in a box sprayed with a new kind of fertilizer has an average height of 26 cm after three days and a standard deviation of 10 cm. One researcher randomly selected 80 such seedlings and calculated the mean height to be 20 cm. Use a=0.05 to test out whether what the plant nursery owner thinks us correct or not.

According to a report from the research for Studying Health System Change, 20% of South Africans delay or go without medical care because of concerns about cost. Suppose that 8 individuals are randomly selected. (a) What is the probability that two individuals will delay or go without medical care? (2) (b) What is the probability that at most two individuals will delay or go without medical care? (3) (c) What is the probability that at least seven individuals will delay or go without medical care? (3)