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:
4) 26+4/842-/×375-^×
5)/^9+37+×+454+12
Step-by-step explanation:
Answer:
D
Step-by-step explanation:
The opposite angles of the inscribed quadrilateral are supplementary
∠A + ∠C = 180 and ∠B + ∠D = 180
∠B + ∠D = 93 + x + 30 = x + 123, hence
x + 123 = 180 ( subtract 123 from both sides )
x = 57 → D
Answer:
126
Step-by-step explanation:
90 / 500 = 0.18 = 18% probability.
So now what is 18% of 700?
0.18 * 700 = 126
Answer:
C. (3, -2)
Step-by-step explanation:
x + y = 1 ➡ x = 1 - y we can use this information in the first equation to find the value of y
3x - 5y = 19 replace x with 1 - y
3 ×(1-y) - 5y = 19 ➡ 3 - 3y - 5y = 19 add like terms
-8y = 16
y = -2 if y is 2 then x is
x + y = 1 ➡ x +(-2) = 1 and x = 3