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.
Answer:
Let x represent number of calling minutes
Step-by-step explanation:
17 + .11x = 22 + .07x
.04x = 5
x = 5/.04 = 125 minutes, is the number of minutes the two plans cost the same
17 + .11*125 = $30.75 is the cost when the two plans cost the same
Answer:
y=-3x+6
Step-by-step explanation:
Answer:
<h2>HJ = 17</h2>
Step-by-step explanation:
The equation:
2 + HI + 12 = 7 + 12
HI + 14 = 19 <em>subtract 14 from both sides</em>
HI = 5
HJ = HI + 12
Substitute the value of HI:
HJ = 5 + 12 = 17
To find the inverse of this function, we first need to replace f(x) with y.
y = 2x^2 + 3
Now, we swap x and y
x = 2y^2 + 3
Now, we solve for y.
-3
x - 3 = 2y^2
Sqrt both sides.
√(x - 3) = 2y
Divide by 2
√(x - 3)/2 = y
Replace y with f^-1(x)
√(x - 3)/2 = f^-1(x)
Just realized you were asking for f(-1), not f^-1(x)
Feels bad.
f(-1) = 2(-1^2 + 3)
f(-1) = 2(-1^5)
f(-1) = 2(-1)
<u>f(-1) = -2</u>
I'm leaving the original answer in case you also need the inverse function. :)