please try to give back the results with in 2 hours, It is time limit test and can be taken once only. It is from the whole Statistics topic, not only one. Thanks. Document Preview: Week 8 : Top of...

Week 8 :
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    1. (TCO 9) The hours of study and the final exam grades have this type of relationship:
ŷ = 7.35(hours) + 34.62. Based on this linear regression equation, estimate the expected grade for a student spending 8 hours studying. Round your answer to two decimal places. (Points : 6)
           58.80
       82.25
       91.97
       93.42
    Answer:
When hours = 8, the expected grade would be
y = 7.35 (8) + 34.62
= 93.42
2. (TCO 5) At a drive through window of a bank it’s found that 10 customers get served every 15 minutes. The bank’s manage is interested in finding a way to increase the number of customers that can be served. He thought that knowing the probability of serving 12 customers per 15 minutes could be helpful to him in the decision making process. Choose the best answer of the following: (Points : 6)
       This is an example of a Poisson probability experiment
       This is an example of a Binomial probability experiment
       This is neither a Poisson nor a Binomial probability experiment
       Not enough information to determine the type of experiment
Answer:
It is an example of Poisson probability experiment
3. (TCO 5) Microfracture knee surgery has a 75% chance of success on patients with degenerative knees. The surgery is performed on 5 patients. Find the probability of the surgery being successful on 3 or 4 patients? (Points : 6)
       0.103516
       0.659180
       0.762695
       0.642875
Answer:
P(x = 3) + P(x = 4) = C(5,3)*(0.75)3*(0.25)2+ C(5,4)*(0.75)4*(0.25)
= 0.2637 + 0.3955
= 0.6592
4. (TCO 5) It has been recorded that 10 people get killed by shark attack every year. What is the probability of having 7 or 8 people get killed by shark attack this year? (Points : 6)
       0.130141
       0.202678
       0.220221
       0.797321
Answer: 
 P (7, 10) + P (8, 10) = e−10107/3! + e−10108/8!
= 0.090079 + 0.112599
= 0.202678
5. (TCO 2) The median teaching hours for a full time faculty at a state university is eight hours per week. What does this tell you about the typical teaching hours for full time faculty at that university? (Points : 6)
       Half of the full time faculties teach less than eight hours per week while half teaches more than eight hours per week.
       The average teaching hours for full time faculty is eight hours per week.
       More full time faculty teaches eight hours per week than any other number of teaching hours.
       The number of teaching hours for full time faculty in not very consistent because eight is such a low number.
6. (TCO 6) 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? (Points : 6)
       2.30
       1.60
       3.10
       -1.60
Answer:
Z = (X - µ)/σ = (27 – 25)/1.25 = 1.60
7. (TCO 8) 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. (Points : 6)
       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.
Answer:
Since p-value is greater than 0.05, we 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.
8. (TCO 8) A result of an entry level exam reveals that more than 22% of students fail that exam.
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. (Points : 6)
       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.
Answer:
Since p-value is greater than 0.02, we fail to reject the null hypothesis. There is not sufficient evidence to support a claim that the true percentage is different from 22%
9. (TCO 2) 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...