SOLUTION: 62% of students in a class are male, seven of the student in the student the class are chosen at random. What is the probability that a) they are all females? b) they are all ma

Algebra ->  Probability-and-statistics -> SOLUTION: 62% of students in a class are male, seven of the student in the student the class are chosen at random. What is the probability that a) they are all females? b) they are all ma      Log On


   



Question 920777: 62% of students in a class are male, seven of the student in the student the class are chosen at random. What is the probability that
a) they are all females?
b) they are all males?
c) at least on is a female?

Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
if 62% are male then 38% are female since 62 + 38 = 100%

probability of all females is equal to .38^7

probability all males is equal to .62^7

probability at least 1 female = 1 - probability all male = 1 - .62^7

^ is the symbol used for exponentiation.

.38^7 means .38 raised to the 7th power.

.38^7 = .0011 rounded to 4 decimal places.
.62^7 = .0352 rounded to 4 decimal places.

1 - .62^7 = 1 - .0352 = .9648 rounded to 4 decimal places.

.38^7 means .38 * .38 * .38 * .38 * .38 * .38 * .38

7 instances of .38 are multiplied by each other.

the number of multiplications performed is 7 - 1 = 6.