The manager of the service department of a local car dealership has noted
that the service times of a sample of 30 new automobiles has a standard
deviation of 6 minutes. A 95% confidence interval estimate for the
standard deviation of the service times for all their new automobiles is
16.047 to 45.722
4.778 to 8.066
2.93 to 6.31
22.833 to 65.059
3.93 to 7.31
6.93 to 10.93
We are interested in determining whether or not the variances of the sales
at two music stores (A and B) are equal. A sample of 26 days of sales at
store A has a sample standard deviation of 30 while a sample of 16 days of
sales from store B has a sample standard deviation of 20. The P-value for
this test is between
0.01 and 0.025
0.025 and 0.05
0.05 and 0.1
0.02 and 0.05
0.05 and 0.1
0.1 and 0.2
We interested in determining whether or not there has been a significant
change in the classifications between the last school year and this school
year. The calculated value for the test statistic equals
0.5444
300
1.6615
6.77
150
1.5444
(Continuing the above problem) The calculated value for the test statistic
equals
2
1.67
3
6
0.67
None of the these answers is correct
In a completely randomized experimental design involving five treatments,
a total of 65 observations were recorded for each of the five treatments.
The following information is provided. SSTR = 200 (Sum Square Between
Treatments) and SST = 800 (Total Sum Square). The mean square within
treatments (MSE) is
50
10
200
600
300
500
(Continuing the above problem) If at a 5% level of significance we want to
determine whether or not the means of the five populations are equal, the
critical value of F is
2.53
19.48
4.98
39.48
1.948
None of these answers is correct
In a random sample of 60 men, 42 reported that they were in favor of team
A to win the Super bowl, while in a sample of 100 women 77 favored team
A to win. The 95% confidence interval for the difference between the
proportions of the two populations is
−0.07 to 0
−0.212 to 0.072
−1.96 to 1.96
0.70 to 0.77
−2.262 to 2.262
None of these answers is correct
(Continuing the above problem) The coefficient of determination equals
0
-0.5
+0.5
-1
1
None of these answers is correct.
In a regression analysis if r2 = 1 , then
SSE = SST
SSE = 1
SSE = -1
SSR = SSE
SSR = SST
None of these answers is correct.
In a multiple regression analysis involving 12 independent variables and
166 observations, SSR = 878 and SSE = 122. The coefficient of
determination is
0.878
0.1389
0.1220
0.7317
0.8389
0.2220
Ten people were given two types of cereal, Brand X and Brand Y. Three
people preferred Brand X, 5 people preferred Brand Y, and 2 people were
undecided. We want to determine whether or not the two products are
equal. To test the null hypothesis, the appropriate probability distribution
to use is
binomial
Poisson
normal
chi-square
F
t distribution
(Continuing the above problem) The hypothesis is to be tested at the 5%
level. The decision rule is not to reject the null hypothesis if
−1.96 < A < 1.96
−1.96 < t < 1.96
−2.262 < t < 2.262
−2.262 < F < 2.262
the number of “+” signs is greater than or equal to 2 and less than or
equal to 6
the number of “+” signs is greater than or equal to 1 and less than or
equal to 7
Given that Y is a normal random variable with a mean of μ = 0 and a
variance σ 2 = 10 . The variance of Y2 is
5
10
50
100
150
200
The random variable x is the number of occurrences of an event over an
interval of ten minutes. It can be assumed that the probability of an
occurrence is the same in any two time periods of an equal length. It is
known that the mean number of occurrences in ten minutes is 5.3. The
expected value of the random variable x is
2
4.3
10
2.30
0
None of these answers is correct.
In order to estimate the average time spent on the computer terminals per
student at a local university, data were collected from a sample of 81
business students over a one-week period. Assume the population standard
deviation is 1.2 hours. With a 0.95 probability, the margin of error is
approximately
0.26
1.96
0.21
1.64
1.21
None of these answers is correct
The probability of rejecting a false null hypothesis is equal to
1 −α
1 −β
α
β
0
None of these answers is correct.
A random sample of 100 people was taken. Eighty of the people in the
sample favored Candidate A. We are interested in determining whether or
not the proportion of the population in favor of Candidate A is significantly
more than 75%. The P-value is
0.2112
0.05
0.025
0.4156
0.3112
None of these answers is correct
An experimental design where the experimental units are randomly
assigned to the treatments is known as
replication
factor block design
random factor design
completely randomized design
partition
experimental condition
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