Answer:
a. P(x>20)=0.19
b. P(x≥6)=0.72
c. P(x≤20)=0.81
d. A and C
Step-by-step explanation:
We know that:
1) the probability that a student makes fewer than 6 mistakes is 0.28
2) The probaiblity that a student makes between 6 to 20 mistakes is 0.53.
We will express the proabilibities in function of the information we have.
a. Probability that a student makes more than 20 mistakes.
b. Probability that the student make 6 or more mistakes
c. Probability that a student makes 20 mistakes at most
d. A and C, because A takes a event of more than 20 mistakes and C takes the event of 20 or less mistakes. Both events cover a probability of 1.