Reference no: EM13582928

Q1. Assuming that the data are normally distributed with a mean of 25 and a standard deviation of 1.25, what is the z-score for a value of 27?

• 2.30
• 1.60
• 3.10
• -1.60

Q2. The mean hours of Internet usage by adults in the US in claimed to be 25 hours per week. A hypothesis test is performed at a level of significance of 0.05 with a P-value of 0.08. Choose the best interpretation of the hypothesis test.

• Reject the null hypothesis; there is enough evidence to reject the claim that the mean of hours Internet usage by adults in the US is 25 hours per week.
• Reject the null hypothesis; there is enough evidence to support the claim that the mean hours Internet usage by adults in the US is 25 hours per week.
• Fail to reject the null hypothesis; there is not enough evidence to reject the claim that the mean hours of Internet usage by adults in the US is 25 hours per week.
• Fail to reject the null hypothesis; there is not enough evidence to support the claim that the mean hours of Internet usage by adults in the US is 25 hours per week.

Q3. In a hypothesis test conducted at a level of significance of 2%, a P-value of 0.035 was obtained. Choose the best interpretation of the hypothesis test.

• Fail to reject the null hypothesis; there is not enough evidence to reject the claim that 22% of students fail the entry level exam.
• Fail to reject the null hypothesis; there is not enough evidence to support the claim that 22% of students fail the entry level exam.
• Reject the null hypothesis; there is enough evidence to reject the claim that 22% of students fail the entry level exam.
• Reject the null hypothesis; there is enough evidence to support the claim that 22% of students fail the entry level exam.

Q4. You want to buy light bulbs and you want to choose between two vendors. Vendor A's light bulbs have a mean life time of 800 hours and a standard deviation of 175 hours. Vendor B's light bulbs also have a mean life time of 800 hours, but a standard deviation of 225 hours. You want light bulbs that have more life time consistency, which vendor will you purchase from?

• Vendor A because you will be more likely get light bulbs with the same life time
• Vendor B because you will be more likely get light bulbs with the same life time
• Either one because both produce light bulbs with the same mean life time.
• Neither one because a mean height of 800 inches is too short for a light bulb.

Q5. A jar contains balls of four different colors; red, blue, yellow and green. The total balls are divides as 45% red, 35% blue, 15% yellow, and 5% green. If you are to select one ball at random. Find the expected value of your winning amount if the payments are set to be $5, $15, $25, $60 for red, blue, yellow and green ball respectively.

Winning amount 5 15 25 60
Probability 45% 35% 15% 5%

• The expected winning amount is $28.50
• The expected winning amount is $14.25
• The expected winning amount is $25.50
• The expected winning amount is $11.25