Answer:
And the margin of error with this one:
Step-by-step explanation:
Assuming that the parameter of interest is the sample mean 
. And we can estimate this parameter with a confidence interval given by this formula:
(1)
For this case the confidence interval is given by (1.9, 3.3)
Since the confidence interval is symmetrical we can estimate the sample mean with this formula:
And the margin of error with this one:
The temperature was -14°F at 8 a.m.
At noon is was 10 degrees warmer - the temperature increase was 10°F
-14°F + 10°F = -4°F
The tempertaure increase between noon and 4 p.m. was twice the previous increase in temperature, which was 10°F.
10°F x 2 = 20°F
We want to know the temperature at 4 p.m. so we just add it up to the previous result.
-4°F + 20°F = 16°F
16°F is the correct answer
Answer: 51
Step-by-step explanation:
Answer: x = 4
Step-by-step explanation:
2x - 3 + 4x = 21
6x - 3 = 21
6x - 3 (+3) = 21 (+3)
6x = 24
24/6
x = 4
Answer:
x=-2.25,y=-2.25
Step-by-step explanation:
The given system is
We want to solve the system for x and y that makes the system true.
Let us multiply the first equation by 3 while maintaining the second equation:
Subtract the current second equation from the first one.
Divide through by 12:
From the second equation we have:
This implies that:
