Answer:
C.
Step-by-step explanation:
Hi there!
To answer this, we must set it up as

Now we just use the distributive property to solve.
this becomes 
I hope this helps!
Answer:
q = 18 ?
Step-by-step explanation:
This is not a complete question but ill give it a shot!
If we are following a pattern then we see q is 11 more than r.
So we do 11 + r (7) to get 18!
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Answer:
Step-by-step explanation:
- Let the speed of the boat be x
- Speed against the current in the river is x - 2
<u>Time in the river:</u>
<u>Time in the lake:</u>
<u>The difference:</u>
Solve for x to find the speed of the boat
<u>Multiply both sides by x(x - 2) to clear the fraction:</u>
- 6x = 15(x - 2) - x(x - 2)
- 6x = 15x - 30 - x² + 2x
- x² - 11x + 30 = 0
- (x - 5)(x - 6) =0
- x -5 = 0, x - 6 = 0
- x = 5 km/h, x = 6 km/h
Answer:
(a) 283 days
(b) 248 days
Step-by-step explanation:
The complete question is:
The pregnancy length in days for a population of new mothers can be approximated by a normal distribution with a mean of 268 days and a standard deviation of 12 days. (a) What is the minimum pregnancy length that can be in the top 11% of pregnancy lengths? (b) What is the maximum pregnancy length that can be in the bottom 5% of pregnancy lengths?
Solution:
The random variable <em>X</em> can be defined as the pregnancy length in days.
Then, from the provided information
.
(a)
The minimum pregnancy length that can be in the top 11% of pregnancy lengths implies that:
P (X > x) = 0.11
⇒ P (Z > z) = 0.11
⇒ <em>z</em> = 1.23
Compute the value of <em>x</em> as follows:

Thus, the minimum pregnancy length that can be in the top 11% of pregnancy lengths is 283 days.
(b)
The maximum pregnancy length that can be in the bottom 5% of pregnancy lengths implies that:
P (X < x) = 0.05
⇒ P (Z < z) = 0.05
⇒ <em>z</em> = -1.645
Compute the value of <em>x</em> as follows:

Thus, the maximum pregnancy length that can be in the bottom 5% of pregnancy lengths is 248 days.