Statistics and Probability Answers

Box A box B both contain the numbers 1,2,3 and 4 contrast the probability mass function and draw the histogram of the sum when one number from each box is take at a time with replacement

two coins are tossed let T the number of tails that occurs determine the values of the random variable T

A political campaign manager wishes to survey a number of voters to estimate the proportion of those who are in favor of his candidate. If a previous survey shows that 55% of registered voters plans to vote for his candidate, what is the minimum sample size required to make his survey accurate with a 95% confidence level and a margin of error of 2.5%?

According to a​ report, 67.4​% of murders are committed with a firearm. ​(a) If 200 murders are randomly​ selected, how many would we expect to be committed with a​ firearm? ​(b) Would it be unusual to observe 147 murders by firearm in a random sample of 200 ​murders? Why?

A manufacturer of apple phone charges claims that only 4% of his production is defective. In a random sample of 120 items, the defect rate is 4.99%. At the 1% level of significance, test the manager's claim.

i. State the null and alternative hypotheses for the test. [2]

ii. Calculate the value of the test statistic for this test. [2]

iii. Determine the critical region(s) for this test. [2]

iv. State the conclusion of this test. Give a reason for your answer. [3]

The 1500 students weight are normally distributed with a mean of 50kg with the standard deviation of S-5 lbs?

A. How many students are less than 46kg

B. How many students are heavier than 113.5lbs

According to a survey, 32% of drivers tailgate other vehicles before passing them (thinking it will incite them to speed up). Consider 45 drivers selected at random. Use a normal approximation to find the probability that:

(a) at least 17 drivers tailgate?  (Use only 3 decimal places)

(b) more than 9 but less than 25 drivers tailgate?  (Use only 3 decimal places) ans_a is 0.251

according to study the average number of hours of tv of viewing per household per week is philippines is 50.4 hours and the standard deviation is 11.8 hours.if a random sample of 42 households is taken what is the probability that the sample average is less than 47.5 hours

A golf ball is selected at random from a golf bag. If the golf bag contains 8 type A​ balls, 5 type B​ balls, and 3 type C​ balls, find the probability that the golf ball is not a type A ball.

The average height of Grade 10 students 148 cm. A sample of 250 male students had an average height of 148.3 cm with a standard deviation of 8 cm. Is there a significant difference between the height of the students?