Download Final M112_Sp06 - Cerritos College

Math112 Elementary Statistics Final Exam 150 pts
Name (Print)______________
Show all calculations, and answer each question fully. Round to three decimal places.
I.
True and False Questions (one point each)
a. The linear correlation coefficient ‘r’ is used to determine the strength of the relationship between
two variables. T or F
b. A correlation coefficient of zero means that the two variables are perfectly correlated. T or
c. The probability of an event can in certain cases be negative. T
or
F
F
d. Under certain condition, it is possible that the sum of the probabilities of all the sample points in the
sample space is less then one. T or F
e. Mutually exclusive means that two events cannot occur together; that is they have no intersection.
T or F
d. If two events are independent , then they are not mutually exclusive. T or F
e. The total area under the curve of any normal distribution is 1.0.
T or F
f. In the notation z(0.05), the number in the parentheses is the measure of the area to the left of the zscore.
T or F
g. The F -distribution is used for inference about the mean when sigma is unknown. T or F
h. The t-distribution is a nonsymmetrical distribution.
T or
i. The F-distribution is a nonsymmetrical distribution.
T
j. The Chi-distribution is a nonsymmetrical distribution.
F
or F
T or F
k. The F-distribution and the Chi-distribution is skewed to the left.
T or F
l. In hypothesis testing, if the test statistic falls in the critical rejoin, you reject null the hypothesis.
T or F
m. A hypothesis is a statement that something is true. T or F
n. The variance under certain conditions can be negative. T or F
o. Standard normal score have a mean of zero and standard deviation of one. T or F
p. The Binomial and Normal distribution are both continuous distributions. T or F
q. There are 50 stars on the American flag . T or
4/30/2017
F
Page 1 of 6
Math112 Elementary Statistics Final Exam 150 pts
Name (Print)______________
Show all calculations, and answer each question fully. Round to three decimal places.
II. Multiple Choices. Circle the right answer! (two points each)
a. Which of the following would be correct hypothesis for testing the claim the the mean cost of a
meal at a fast food restaurant is less then $3.79?
A. H0 :   3.79, H a :   3.79
B. H0 :   3.79, H a :   3.79
C. H 0 :   3.79, Ha :   3.79
D. H0 :   3.79, Ha :   3.79
b. You have conducted a hypothesis test and found that p=0.04. Based on this information you know
that you can reject the null hypothesis if.
A.   0.04
B.  > 0.04
C.   0.04
c. The measurement of a random sample of 30 female college students produced an average height
of 66 inches and a standard deviation of 2.5 inches. The correct symbol for 2.5 inches is:
A. x
B. s
C. 
D. 
d. ANOVA is used to compare two or more:
A.
B.
C.
D.
III.
population variances
population proportions
populations medians
population means
An urn contains 6 red marbles, 5 white marbles, and 7 blue marbles. Six marbels are drwn at
random from the urn, one at a time, without replacement.
a. Find the probability of getting the sequence “red, white, white, white, blue, blue, blue”
4/30/2017
Page 2 of 6
Math112 Elementary Statistics Final Exam 150 pts
Name (Print)______________
Show all calculations, and answer each question fully. Round to three decimal places.
b. Find the probability of getting the combination “ 1 red, 2 white, 3 blue”
IV.
Given the bivariate data, complete the table and find
(a) SS(x)=
(b) SS(y)=
c. SS(xy)=
x
2
5
6
7
y
1
3
6
5
x2
y2
xy
d Find r, the coefficient of linear correlation.
(e) Find the equation of line of best fit in the form
y=mx+b
(f) Predict y if x= 5
V.
Let x be the number of successes in n=7 independent binomial trials, where the probability of
success in one trial is p = .4. Find the probability P(x > 5) using the appropriate formulas.
VI.
Events E and F have probabilities P(E)=0.5, P(F)=0.4 and P(E and F)=0.2.
i. Find P(E or F)
ii. Find P(E|F)
4/30/2017
Page 3 of 6
Math112 Elementary Statistics Final Exam 150 pts
Name (Print)______________
Show all calculations, and answer each question fully. Round to three decimal places.
iii. Are E and F mutually exclusive?
iv. Are E and F independent? Explain
VII. The pulse rate for 10 adult women were:
60, 72, 58, 78, 66, 82, 78, 99, 70, 80
a. Find the sample mean
b. Find the sample standard deviation
c. Find 90% CI to estimate the true mean pulse rate for women based on this sample
VIII.
The random variable Y is normally distributed, with mean 25 and standard deviation 8.
Find P (Y ≥ 31)
4/30/2017
Page 4 of 6
Math112 Elementary Statistics Final Exam 150 pts
Name (Print)______________
Show all calculations, and answer each question fully. Round to three decimal places.
IX.
(12 points). The weights of 19 boxes of cereal are measured. The sample standard
deviation is 0.18 ounces. The sample mean is 14.91 ounces. We are concerned that the
mean weight of all boxes may be under 15 ounces. Assume that the weights of the cereals
are normally distributed.
i. State the null and alternative hypothesis
ii. Test the null hypothesis at the 5% level, using either p-value or classical
approach, showing calculation of the test statistic.
X.
In a sample of 70 students, 42 plan to graduate next year. Find the 90% confidence interval
for the percentage of students planning to graduate next year.
XI.
In a test of drugs A and B, the following results were obtained. Test the hypothesis that
there is no difference between the two drugs at 5% level.
Drug A
Drug B
4/30/2017
Worse
34
17
Same
11
12
Improved
12
18
Page 5 of 6
Math112 Elementary Statistics Final Exam 150 pts
Name (Print)______________
Show all calculations, and answer each question fully. Round to three decimal places.
4/30/2017
Page 6 of 6