Answer:
D. x^2 +14x + 40
Step-by-step explanation:
(x+4)(x+10)
x^2+10x+4x+40
x^2+14x+40
Answer:
50
Step-by-step explanation:
.80n = 40
n = 40 divided by .80
40/8/10 = 400 / 80 = 50
Best Of Luck,
- I.A. -

It looks like your first selection (a) is appropriate.
Answer:
A. T > 2.539
Step-by-step explanation:
We have a hypothesis test of the mean, with unknown population standard deviation.
The hypothesis are:

From the hypothesis we can see that the test is right-tailed, so the critical value of t should be a positive value.
The degrees of freedom can be calculated as:

The significance level is 0.01, so the critical value tc should be the one that satisfies:

Looking up in a t-table, for 19 degrees of freedom, this critical value is tc=2.539.