Posted by tanya on .
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 
Reiny,
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 
Anonymous,
. 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 
Anonymous,
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 .