Answer:
What I think are the answers are C,D, and A, hope this helps.
Step-by-step explanation:
Two hundred thirty-five and six hundred seventy-eight thousandths
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:
add 15 to both sides
Step-by-step explanation:
Answer: it depends
Step-by-step explanation: