Which of these hypotheses is the most appropriate alternative hypothesis for this problem? (Q2)
A: h = lB: H > LC: H = LD: H < LE: h < lF: h > l
(Q3) Suppose that the population distributions of the number of emails sent in the byhigh-speed-connection customers and by low-speed-connection customers both arenearly normal. Which of the following have probability histograms that can beapproximated well by a normal curve, after transforming to standard units? (select allthat apply)

Suppose we construct a Z statistic by transforming H-L to standard units
(approximately). Under the alternative hypothesis, the expected value of Z would be
(Q4)
A: Negative
B: zero
C: Positive
So we should (Q5)
A: consult a statistician
B: use a left-tail test
C: use a right-tail test
D: use a two-tail test
To test the null hypothesis at significance level 10%, we should reject the null
hypothesis if (Q6)
A: the z-score
B: the absolute value of the z-score
(Q7)
A: less than
B: greater than
(Q8)
(Q8)
1.28
(continues from q6 and q7)
For high-speed-connection customers, the sample mean number of emails in the
month is 293, and the sample standard deviation of the number of emails in the month
is 117. For low-speed-connection customers, the sample mean number of emails in
the month is 274, and the sample standard deviation of the number of emails in the
month is 135.
The estimated standard error of H - L is (Q9)
2
2
117
135
91.1925
9.5495
300
400
.
The z-score is (Q10)
293
274
19
1.99
9.5495
9.5495
H
L
H
L
z
SE
.