Answer:
The null and alternative hypotheses are:


Under the null hypothesis, the test statistic is:

Where:
is the sample mean
is the sample standard deviation
is the sample size

Now, the right tailed t critical value at 0.05 significance level for df = n-1 = 10-1 = 9 is:

Since the t statistic is less than the t critical value at 0.05 significance level, therefore,we fail to reject the null hypothesis and conclude that there is not sufficient evidence to support the claim that the average phone bill has increased.
Answer:
36
Step-by-step explanation:
Since E is the midpoint, AE and EB are equal. We can write this as such,
4x+6=10x-12 if we solve from here we get 6x=18. Simplify to get x=3. sub in three for x in the AE equation, 4(3)+6 and solve. You'd get 18 as your answer. Double that to get the solution since AE= 1/2AB. 18*2= 36
AB=36
Answer:
90
Step-by-step explanation:
Answer:
y = 7/2x - 20.
Step-by-step explanation:
The slope of the given line is -2/7, therefore the slope of the line perpendicular to it is - 1/ -2/7 = 7/2.
When x = -4, y = -6 so we substitute x1 = 4, y1 = -6 and m ( the slope) = 7/2 in the point slope form of a line:
y - y1 = m(x - x1)
y - (-6) = 7/2(x - 4)
y + 6 = 7/2x - 14
y = 7/2x - 20.