problem library | Page 2 | MathCelebrity Forum

# problem library

1. ### If you are running 6 miles per hour, then it takes you 10 minutes to run 1 mile. If you are running

If you are running 6 miles per hour, then it takes you 10 minutes to run 1 mile. If you are running 8 miles per hour, it takes you 7.5 minutes to run a mile. What does your speed have to be for your speed in miles per hour to be equal to your mile time in minutes? From above, we have: 6mph...
2. ### If an experiment is conducted with 5 conditions and 6 subjects in each condition, what are dfn and d

If an experiment is conducted with 5 conditions and 6 subjects in each condition, what are dfn and dfe? a = Number of groups/conditions = 5 dfn = a - 1 don = 5 - 1 dfn = 4 N = 5 * 6 = 30 dfe = N - a dfe = 30 - 5 dfe = 25
3. ### True or False: The standard deviation of the chi-square distribution is twice the mean.

True or False: The standard deviation of the chi-square distribution is twice the mean. False, the variance is twice the mean. Mean is k, Variance is 2k
4. ### Men's heights are normally distributed with mean 69.0 inches and standard deviation 2.8 inches. Mimi

Men's heights are normally distributed with mean 69.0 inches and standard deviation 2.8 inches. Mimi is designing a plane with a height that allows 95% of the men to stand straight without bending in the plane. What is the minimum height of the plane? Using the empirical rule calculator, we...
5. ### A high school with 1000 students offers two foreign language courses : French and Japanese. There ar

A high school with 1000 students offers two foreign language courses : French and Japanese. There are 200 students in the French class roster, and 80 students in the Japanese class roster. We also know that 30 students enroll in both courses. Find the probability that a random selected student...
6. ### Assume that you make random guesses for 5 true-or-false questions

Assume that you make random guesses for 5 true-or-false questions. (a) What is the probability that you get all 5 answers correct? (Show work and write the answer in simplest fraction form) (b) What is the probability of getting the correct answer in the 5th question, given that the first four...
7. ### What is the range of possible values for a coefficient of correlation?

What is the range of possible values for a coefficient of correlation? The range is -1.0 to +1.0
8. ### What can we conclude if the coefficient of determination is 0.94?

What can we conclude if the coefficient of determination is 0.94? Strength of relationship is 0.94 Direction of relationship is positive 94% of total variation of one variable(y) is explained by variation in the other variable(x). All of the above are correct 94% of total variation of one...
9. ### If the correlation between two variables is close to minus one, the association is: Strong Moderate

If the correlation between two variables is close to minus one, the association is: Strong Moderate Weak None Strong - Coefficient near +1 or -1 indicate a strong correlation
10. ### The coefficient of determination is found by taking the square root of the coefficient of correlatio

The coefficient of determination is found by taking the square root of the coefficient of correlation. True or False FALSE - It is found by squaring the coefficient of correlation
11. ### In simple linear regression the slope and the correlation coefficient will have the same signs True

In simple linear regression the slope and the correlation coefficient will have the same signs True False FALSE - Only if they are normalized
12. ### Ms. Jeffers is splitting \$975 among her three sons. If the oldest gets twice as much as the youngest

Ms. Jeffers is splitting \$975 among her three sons. If the oldest gets twice as much as the youngest and the middle son gets \$35 more than the youngest, how much does each boy get? Let 0 be the oldest son, m be the middle sun, and y be the youngest son. Set up our given equations o = 2y m = y...
13. ### A box contains 22 red apples and 3 green apples. Three apples are selected at random, one after the

A box contains 22 red apples and 3 green apples. Three apples are selected at random, one after the other, without replacement. please show the steps. (a) The first two apples are green. What is the probability that the third apple is red? (b) What is the probability that exactly two of the...
14. ### Jazmin is a hairdresser who rents a station in a salon for daily fee. The amount of money (m) Jazmin

Jazmin is a hairdresser who rents a station in a salon for daily fee. The amount of money (m) Jazmin makes from any number of haircuts (n) a day is described by the linear function m = 45n - 30 A) A haircut costs \$30, and the station rent is \$45 B) A haircut costs \$45, and the station rent is...
15. ### T-shirts sell for \$19.97 and cost \$14.02 to produce. Which equation represents p, the profit, in ter

T-shirts sell for \$19.97 and cost \$14.02 to produce. Which equation represents p, the profit, in terms of x, the number of t-shirts sold? A) p = \$19.97x - \$14.02 B) p = x(\$19.97 - \$14.02) C) p = \$19.97 + \$14.02x D) p = x(\$19.97 + \$14.02) B) p = x(\$19.97 - \$14.02) Profit is Revenue - Cost...
16. ### A bag contains 10 red balls, 10 green balls and 6 white balls. Two balls are drawn at random from th

A bag contains 10 red balls, 10 green balls and 6 white balls. Two balls are drawn at random from the bag without replacement. What is the probability that they are of different colours? The key phrase here is without replacement. First, it's easier to find the probability of both colors...
17. ### If 13,754 people voted for a politician in his first election, 15,420 voted for him in his second el

If 13,754 people voted for a politician in his first election, 15,420 voted for him in his second election, and 8,032 voted for him in the first and second elections, how many people voted for this politician in the first or second election? Let P(A) be the first election votes, P(B) be the...
18. ### Determine if the statement below is True or False

Determine if the statement below is True or False If B ⊂ A, then A ∩ B = B Is this statement True or False? True: If B ⊂ A, then B ∈ A So A ∩ B is the similar elements of both. B contains itself as a subset. So this is true
19. ### From a standard 52 card deck, how many 6-card hands will have 2 spades and 4 hearts?

From a standard 52 card deck, how many 6-card hands will have 2 spades and 4 hearts? We want the product of 13C2 * 13C4 since we have 13 possible spades choose 2 and 13 possible hearts choose 4 Spades: 13C2 from our combinations calculator = 78 Hearts: 13C4 from our combinations calculator =...
20. ### Find the elements on the principal diagonal of matrix B

Find the elements on the principal diagonal of matrix B Matrix B: |0 0 8| |-1 3 0| |2 -5 -7| The main diagonal is any entry where row equals column |0 0 8| |-1 3 0| |2 -5 -7| In this case, it is 0, 3, -7