***Please provide excel attachment

1. A random sample of 49 observations from a normal population yields a sample mean of

85 with a standard deviation of 14.

(a) Test the claim that the population mean differs from 81. Use a 0.05 significance

level.

(b) Test the claim that the population mean is greater than 85. Use a 0.05 significance

level.

2. The following data were sampled from a normally distributed population. At the 10%

significance level, is there evidence to indicate that the mean of the population differs

from 16?

12 15 14 19 15 20 16

3. A Washington, D. C., think tank announces the typical teenager sent 50 text messages

per day in 2009. To update the estimate, you phone a sample of teenagers and ask them

how many text messages they sent the previous day. Their responses were:

51 175 47 49 44 54 145 203 21 59 42 100

At 0.05 level, can you conclude that the mean number is greater than 50? Estimate the

p-value and describe what it tells you.

4. The National Safety Council reported that 52% of American turnpike drivers are men. A

sample of 300 cars traveling southbound on the New Jersey Turnpike yesterday

revealed that 170 were driven by men. At the 0.01 significance level, can we conclude

that a large a larger proportion of men were driving on the New Jersey Turnpike than

the national statistics indicate?

5. A recent article in The Wall Street Journal reported that the 30-year mortgage rate is

now less than 6%. A sample of eight small banks in the Midwest revealed the following

30-year rates (in percent):

4.8 5.3 6.5 4.8 6.1 5.8 6.2 5.6

At 0.10 level, can you conclude that the 30-year mortgage rate is now less than 6%