Answer is b
it was rotated 90 degrees counterclockwise.
Answer:
Addition Property of Equality
Step-by-step explanation:
Given expression:
To find the missing justification.
We will evaluate the given expression and justify the step.
Using Addition Property of Equality( by this property of equality we can add a number to both sides of the equation without effecting the equality of the equation)
Adding 
to both sides of the equation.
Answer:
The standard deviation has changed for the worse
Step-by-step explanation:
We need to compare the sample standard deviation of 52.3 to the known population standard deviation of 43.7. The test we will use will use Chi-Square distribution...
The hypothesis for this test are...
H0: σ = 43.7
Ha: σ ≠ 43.7
This is a 2 tailed test.
We have n = 81
s = 52.3
s² = 52.3² = 2735.29
σ = 43.7
σ² = 1909.69
The degrees of freedom are: n - 1, in this case, 80
Our significance level is 95%, so our critical values are
Χ² < 57.153 and Χ² > 106.629
The test static is found with the formula:
Χ² = [(n - 1)s²]/σ²
Plug in what we have and find the test stastic....
Χ² = [80(2735.29)]/1909.69
Χ² = 114.586
114.586 > 106.629, we reject the null hypothesis. There is evidence that shows that the standard deviation has changed. The evidence suggests that it has increased, which would make the new method worse than the old method.
