Answer:

Step-by-step explanation:
Since the population standard deviation
, is known, we use the z confidence interval for the mean.
This is given by:

For a 95% confidence interval we use
.
It was also given that:
,
and 
Let us substitute the values to get:


<u>Interpretation:</u>
We can say with 95% confidence that the interval between 1463.3 and 1580.7 SAT scores contains the population mean based on the sample 125 SAT scores.
Ik that 9 is one of em
Hope this helps have a nice nite
Answer:
The percent of change in 6 yards to 36 yards is 500% .
Step-by-step explanation:
Formula

Where
Change in value = Final value - initial value
As given
The percent of change in 6 yards to 36 yards.
Final value = 36 yards
initial value = 6 yards
Change in value = 36 - 6
= 30 yards
Put in the formula


Percentage = 500%
Therefore the percent of change in 6 yards to 36 yards is 500% .
Answer:
9 mph = the speed in still water
Step-by-step explanation:
Let r = the speed in still water
Then the speed going down stream is r + 3
and the speed going upstream is r - 3
d = rt or t = d/r
time going downstream is 16/(r + 3) and time going upstream is 16/(r - 3)
The total time was 4 hours, so
Multiply thru the equation by (r + 3)(r - 3)
Then 16(r - 3) + 16(r + 3) = 4(r + 3)(r - 3)
16r - 48 + 16r + 48 =
- 36
- 36 = 32r
- 32r - 36 = 0

4(r - 9)(r + 1) = 0
r = 9 or -1
But a rate of speed cannot be negative, so x ≠ -1
So, r = 9 mph = the speed in still water
Answer:
The wall is 3 ft high and 5 ft long.
Step-by-step explanation:
Recall: Area of the rectangular wall is A = (length)(height).
Let the height be represented by h. Then the length is represented by h + 2.
The formula A = (length)(height) then becomes A = h(h+2) = 15 ft², which, written in the standard form of a quadratic equation, is h² + 2h - 15 = 0.
Let's solve this last equation for h using completing the square:
h² + 2h - 15 = 0 becomes h² + 2h + 1 -1 - 15 = 0, or (h + 1)² = 16. Taking the square root of both sides, we get:
h + 1 = ±4, which is equivalent to h = 3 and h = -5. Discard the negative result. Then h = 3 and w = 3+2 = 5.
The wall is 3 ft high and 5 ft long. Its area is (3 ft)(5 ft) = 15 ft²