We can first find the total number of quizzes and the number he got them right:
Total number: 20+80=100
Total correct answer:
20×60%+50×80%
=52
We can then find the percentage:

Therefore the answer is 52%.
Hope it helps!
Answer:
Probability = 0.0228
Step-by-step explanation:
Let X be a random variable which is a measure of the time to get a passenger on board.
Mean(u) = 22.5mins
Standard deviation (s) = 5.25mins
X = 33mins
From Pr(X>33), starting from Pr(X = 33)
For normal distribution, Z = 7(X - u) /s
Z= (33 -22.5) /5.25
= 10.5/5.25
= 2
From the normal distribution table, 2 = 0.4772
Recall that
If Z is positive,
Pr(x>a) = 0.5 - table value
Pr(x<a) = 0.5 + table value
Therefore;
Pr(X>33) = 0.5 - 04772
= 0.0228
Answer:
non- function
Step-by-step explanation:
any X being REPEATED (the first number of each pair) is non-function.