# statistics - math

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Sixty percent of the students at a particular community college are female.
If 13 students at that community college are selected at random,
find the probability that 5 or 6 students will be female.
Use Appendix Table or Excel function for Binomial distribution.
[Remember from previous test: P(5 or 6) = P(5) + P(6) ]

• statistics - math - ,

I don't have your Appendix, nor do I know which Excel function you are talking about, but ..

Prob (female) = 60/100 = 3/5
prob (male) = 2/5

prob (5 of 13 are female) = C(13,5)(3/5)^5 (2/5)^8
= 1287 (.07776)(.0006553) = .06559

do prob(6 of 13 are female) the same way and add up the 2 results.

• statistics - math - ,

. The ratio of x to y is 3:1.

a. When x is 9, y is .
Hint: If the answer is a fraction, use the format x/y.

• statistics - math - ,

10. The ratio of x to y is 3:1.

a. When x is 9, y is .
Hint: If the answer is a fraction, use the format x/y.

11. b. When x is 3, y is .
Hint: If the answer is a fraction, use the format x/y.

12. c. When x is 1, y is .
Hint: If the answer is a fraction, use the format x/y.

13. In a right triangle, the ratio of side a to side b is 2:1.

a. When side b is 2 inches, side a is ".

14. b. When side b is 2 inches, side c is ".

Hint: Draw a right triangle and label the sides. Use the Pythagorean theorem to find the length of side c to two decimal places.

15. A rectangle has a ratio of L:W = 1:3.

a. Side L = 6 inches, so side W = inches.

16. b. The area of the rectangle is square inches.

17. The ratio of any circleâ€™s radius to its diameter is 1:2.

When a circle has a radius of 2, its diameter is .
Hint: If the answer is a fraction, use the format x/y.

18. When a circle has a radius of 1, its diameter is .
Hint: If the answer is a fraction, use the format x/y.

19. When a circle has a radius of 8, its diameter is .
Hint: If the answer is a fraction, use the format x/y.

20. When a circle has a diameter of 4, its radius is .