Answer:
Step-by-step explanation:
This is a question on hypothesis testing.
Population mean based on 30 year average for July was 90 with
a std deviation of 2.1
Sample of 5 shows average 93.5
To check whether sample average = population average
H0: x bar =90
Ha: x bar not equal 90(Two tailed test)
Test statistic = 
=3.73
Since this lies outside the range (-1.96, 1.96) we reject null hypothesis
Hence we cannot say sample mean equals 90
Answer:
-14°F
Step-by-step explanation:
First, we start at 12°f. Then, the temperature changes by -26°f. This means that we add (-26°f) to what we currently have. We then have
12 + (-26)
= 12-26
= -14°F
Answer: x=-4
Step-by-step explanation:
Given
7(2x+5)=4x-9-x
Expand parenthesis
14x+35=4x-9-x
Combine like terms
14x+35=3x-9
Subtract 35 on both sides
14x+35-35=3x-9-35
14x=3x-44
Subtract 3x on both sides
14x-3x=3x-44-3x
11x=-44
Divide 11 on both sides
11x/11=-44/11
x=-4
Hope this helps!! :)
Please let me know if you have any questions