Answer:

Step-by-step explanation:
This situation can be modeled by a binomial distribution of parameters:

We want to find the probability that at least 90 are in repair.
<u><em>We can approximate this problem to a normal distribution, where:</em></u>



Then we look for

Then we must find the normal standard statistic Z-score

Therefore:

Looking in the standard normal table we obtain:

Answer:
D. 0.1353
B. 0.0473
Step-by-step explanation:
For an exponentially distributed random variable, the cumulative distribution function is:

with parameter λ=2, then P(X≥1) is equal to:

D. 0.1353
with parameter λ=1.5, then P(2≤X≤4) is equal to
B. 0.0473
<em><u>3 x 12 </u></em>
<em><u>I think because you find out how to graph in the corresponding area on the graph </u></em>
Answer:
1/2x +7
Step-by-step explanation:
Let the unknown number be x
We want 1/2 of the number
1/2x
Then 7 more than (add)
1/2x +7