Answer:
22.7604763 degrees
Step-by-step explanation:
Note that the answer is NOT 20 degrees.
She adjusted the ramp to half the original <em>incline</em>
Therefore we have tan 40 = x = 0.839099631.
We want an incline of y degrees where tan y = x/2 = 0.839099631/2 = 0.419549815
Taking the arctan of both sides, we get
y = arctan(0.419549815) = 22.7604763 degrees
We can use the binomial theorem to find the probability that 0 out of the 15 samples will be defective, given that 20% are defective.
P(0/15) = (15C0) (0.2)^0 (1 - 0.2)^15 = (1)(1)(0.8)^15 = 0.0352
Then the probability that at least 1 is defective is equal to 1 - 0.0352 = 0.9648. This means there is a 96.48% chance that at least 1 of the 15 samples will be found defective. This is probably sufficient, though it depends on her significance level. If the usual 95% is used, then this is enough.
1/6 for the first question and 1/3 for the second
3 terms are in the expression
