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1 answer:
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Answer:
38 degrees
Step-by-step explanation:
By the Law of Cosines,
5² = 3² + 7² - 2(3)(7) cos A
5² - 3² - 7² = -2(3)(7) cos A
-33 = -42 cos A
cos A = 33/42
A = arccos(33/42), which is about 38 degrees.
Answer:
0.15866.
Step-by-step explanation:
We have been given that on average, electricians earn approximately μ= $54,000 per year in the united states. Assume that the distribution for electricians' yearly earnings is normally distributed and that the standard deviation is σ= $12,000. We are asked to find the probability that the sample mean is greater than $66,000.
First of all, we will find the z-score corresponding to 66,000 using z-score formula.
Now, we need to find the probability that z-score is greater than 1 that is .
Upon using formula , we will get:
Upon using normal distribution table, we will get:
Therefore, the probability that the sample mean is greater than $66,000 would be 0.15866 or approximately .