THE ANSWER IS B...... I JUST TOOK THE TEST
I'll leave the computation via R to you. The are distributed uniformly on the intervals , so that
each with mean/expectation
and variance
We have
so that
Now,
and
We have
because and are independent when , and so
giving a variance of
and so the standard deviation is
# # #
A faster way, assuming you know the variance of a linear combination of independent random variables, is to compute
and since the are independent, each covariance is 0. Then
and take the square root to get the standard deviation.
A={January,march,may,july,august,october,december}
Put one dot on (0,-2) , (4,0), (-4,-4) connect the dots that is your graph line.
Slope is 1/2 and you is -4
Answer:
152 Chairs
Explanation:
7 rows of 23 chairs: 7 · 23
7 · 23 = 161
Remove 9
161 - 9 = 152