It is given the probability that a dancer like ballet is 0.35
So, P(B) = 0.35
It is given the probability that a dancer like tap is 0.45
So, P(T)= 0.45
The probability that he likes both ballet and tap is 0.30
So,
the probability that the dancer likes ballet if we know she likes tap. This is the case of conditional probability.
So,
= 0.666
= 0.67
Therefore, the probability that the dancer likes ballet if we know she likes tap is 0.67.
Option 3 is the correct answer.
Answer:
a) 0.023
b) 0.286
c) 10 students will be unable to complete the exam inthe allotted time.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 80 minutes
Standard Deviation, σ = 10 minutes
We are given that the distribution of time to complete an exam is a bell shaped distribution that is a normal distribution.
Formula:
a) P(completing the exam in one hour or less)
P(x < 60)
Calculation the value from standard normal z table, we have,
b) P(complete the exam in more than 60 minutes but less than 75 minutes)
c) P(completing the exam in more than 90 minutes)
P(x > 90)
Calculation the value from standard normal z table, we have,
15.87% of children of class will require more than 90 minutes to complete the test.
Number of children =
Approximately, 10 students of class will require more than 90 minutes to complete the test.