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:
Two 50 bottles
Step-by-step explanation:
because the 50 bottles is more cheaper than buying a n 80 ml bottle,
it's just a waste of money.
Probability of an event= number of ways an event can occur / total number of possible outcomes.
Probability = 6/12 = 0.5
Answer:
A plot would be very useful to solve the question.
Step-by-step explanation: