Statistics and Probability Answers

1.     What is the probability of getting a total of 7 or 11 when a pair of fair dice is tossed?

2.     In a certain industrial facility , accidents occur in frequently. It is known that the probability of an accident on any given day is 0.005 and accidents are independent of each other.

a)     What is the probability that in any given period of 400 days , there will be an accident on one day?

b)    What is the probability that in any given period of 400 days , there are at most three days with an accident?

1.     Generate 4 random numbers by using linear congruenital generator.Use X₀ = 21, a= 17, c=43, m=105.

A written form of assessment is most appropriate in Grade R mathematics and should be used in assessing every concept. To what extent do you agree or disagree with the statement? Give reasons

A sample of 60 Grade 9 students’ ages was obtained to estimate the mean age of all Grade 9 students. =15.3 years and the population variance is 16.

1.) What is the point estimate for ?

2.) Find the 95% confidence interval for .

3.) Find the 99% confidence interval for .

4.) What conclusions can you make based on each estimate?

A classroom has 15 seats. The front row has 5 seats, the second row has 6 seats and the third row has 4 seats. 9 students are to be seated in the classroom.

a)In how many ways can they be seated?

b)3 of the students are short are short-sighted and must sit in the front row. The other students are free to sit anywhere. In how many ways can the students be seated?

If population mean and standard deviation is 100 and 10 respectively. And sample mean is 115 and n = 30 then what is z score?

A human resources manager for a car company wanted to know whether production-line workers have more days absent than office workers. He took a random sample of eight workers from each category and recorded the number of days absent the previous year. Can we infer that there is a difference in days absent between the two groups of workers? (at 10% significance level) Production-line workers 4 0 6 8 3 11 13 5 Office workers 9 2 7 1 4 7 9 8

Suppose, the average U. S. household spends $90 per day. You recently took a random sample of 30 households in Huntsville and the results revealed a mean of $84.50. Suppose the SD is known to be $14.50. Using a 0.05 level of significance, can it be concluded that the average amount spent per day by U.S. households has decreased

A bag contains 3 white, 1 black and 3 red ball. Two balls are drawn from the well shaked bag. Find the probability of both the balls being black and its mean.    

a company produced ethyl el alcohol and claimed to jave a mean alcohol content of 70%.A random sample of 80 of ethyl alcohol bottles was taken as sample to verify this claim.it was found out that the mean alcohol content is 65% with a standard deviation of 2%. test the claim at 5% level of significance and assume that the population is normallt distributed