Statistics and Probability Answers

the probability that a flight arrives on time is 0.7 and the probability that a flight departs on time is 0.8.The probability that a flight neither arrives on time nor departs on time is 0.15. Then the probability that flight arrives on time and departs on time is?

Two TVs are randomly selected from a large shipment. Each has a 0.03 probability of being defective. Calculate Pr{ both good }.

1.3.Blood glucose levels for obese patients have a mean of 100 with a standard deviation of 15. A
researcher thinks that a diet high in raw cornstarch will have a positive or negative effect on blood
glucose levels. A Sample of 30 patients who have tried the raw cornstarch diet has a mean glucose
level of 140.
Test the hypothesis that the raw cornstarch had an effect.

14. A particular type of printer cartridge is produced by 2 companies – HP cartridge and Dell Cartridge. Suppose that HP produces 65 % of the cartridges and that dell produces 35 % of the cartridges. 8 % of the cartridges produced by HP are defective and 12 % of the Dell cartridges are defective. A customer purchases a new cartridge what is the probability that HP produced the cartridge? What is the probability that Dell produced the cartridge? The cartridge is tested and found to be defective. Now what is the probability that HP produced the cartridge? Or Dell produced the cartridge?

Graph: https://imgur.com/a/4JYT0u6

A researcher examined the relationship between Variables X and Y among 150 male subjects, and he graphed a scatter plot as seen below. The correlation coefficient for all the 150 data points is about 0.5. Let K be the correlation coefficient for the data points with X values lying between 130 to 150. Which of the following statements is correct?

A. K is less than 0.50.
B. K is more than 0.50.
C. None of the other options.

A researcher examined the relationship between weight (y axis) and height (x axis) among 475 male subjects. He graphed the relationship in the scatter diagram below. Weight is measured in pounds, and height in inches.

Graph: https://imgur.com/a/aINFHJx

The equation of the regression line is y = 3.86*x – 110.42. Is it reasonable to presume that if a male is 107 inches tall, his weight will be 302.6 pounds?

A. Yes
B. No

Graph: https://imgur.com/a/33aOkQZ

A researcher examined the relationship between Variables X and Y among 20 male subjects, and he graphed a scatter plot as seen below. One of the lines (A, B, C, or D) is the regression line for predicting Y from X. Which one is it?

If p1=p(A),p2=p(B),p3=P(A ∩ B), (p1,p2,p3>0) express the following in terms of p1,p2,p3

1)P(A ∪ B)'
2)P(A'∪ B')
3)P(A' ∩ B)
4)P(A' ∪ B)
5)P(A' ∩ B')
6)P(A ∩ B')
7)P(A | B)
8)P(B | A')
9)P[A' ∩ (A ∪ B)]

1.1.A college professor randomly selects 25 freshmen to study the mathematical background of the
incoming freshman class. The average SAT score of these 25 students is 565 and the standard deviation
is estimated to be 40. Using this information, can the professor reject the null hypothesis that the
average test score is 550 or less?
Use a 5 % level of significance.
1.2.Suppose the college professor in question 1.1. wants to know whether the mathematical aptitude
of freshmen has improved over the past year. He randomly draws 25 SAT mathematics scores from
last year’s freshman class and obtains a sample mean of 560 and a sample standard deviation of 35.
Compare the results from last year with the results from this year. Do the data offer enough evidence
for rejecting the null hypothesis that there is no improvement?
Use a 5 % level of significance.