a. A simple random sample of size 80 has a mean of 7.31. The population standard deviation is 6.26. Construct a 99% confidence i
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Answer:
30% is the correct answer.
Step-by-step explanation:
Total number of boys = 2
Total number of girls = 3
Total number of students = 5
To find:
Probability that the pianist will be a boy and the alternate will be a girl?
Solution:
Here we have to make 2 choices.
1st choice has to be boy (pianist) and 2nd choice has to be girl (alternate).
Formula for probability of an event E is given as:
For , number of favorable cases are 2 (total number of boys).
Total number of cases = Total number of students i.e. 5
So, is:
For , number of favorable cases are 3 (total number of girls).
Now, one boy is already chosen as pianist so Total number of cases = Total number of students left i.e. (5 - 1) = 4
So, the required probability is: