1. For 200 children with a test for E. histolytic, 59 had positive result and 151 had negative result
a) What is the probability of positivity for E. histolytic?
b) Probability of negativity for E. histolytic was:
c) Probability for positive or negative result was:
2. In a blood bank, they determined blood groups:
|
Group
|
n
|
%
|
|
0
|
45
|
45
|
|
A
|
29
|
29
|
|
B
|
21
|
21
|
|
AB
|
5
|
5
|
|
Total
|
100
|
100
|
a) What is the probability of being part of the 0 group?
b) What is the probability of choosing a person from the B group and then someone from the A group?
3. There are 100 new born in a maternity in Celaya. 55 were females and 45 males
a) What is the probability of randomly choosing a female baby for a study?
b) What is the probability of choosing a male baby?
c) What is the probability of choosing a female or a male baby?
4. A bag contains 5 yellow marbles, 16 green marbles, and 2 red marbles.
a) What is the chance of drawing a red marble?
b) What is the probability of drawing a green marble without replacement and after drawing a yellow marble?
5. A fruit basket contains five red apples and three green apples. Without looking, you randomly select two apples, without replacement. What is the probability that
a) You will select two red apples?
b) You will not select two green apples?