stat101 multiple chose

1-A small sample of computer operators shows monthly incomes of $1,950, $1,885, $1,965,
$1,940, $1945, $1895, $1,890 and $1,925. The class width of the computer operators’ sample
with 5 classes is $16.
True
False
2-The frequencies of favourite car colors (White, Black, Grey, Red) can be represented using a
histogram.
True
False
3-The following Table describes a probability distribution:
x
0
1
2
3
P(x)
0.15 0.18 0.32 0.35
True
False
4-The expected value of a discrete random variable represents the mean value of the outcomes.
True
False
5-If for a distribution Q1=13, Q2=14 and Q3=15.5. Then the Interquartile range is 2.5
True
False
6-If A and B are mutually exclusive events, then P(A or B) = P(A) + P(B)
True
False
7-The random variable X has the following probability distribution:
x
0
1
P(x)
0.2
0.6
The variance of this distribution is
2
0.2
1.0
0.4
0.1
1.4
8-If a random variable X has a binomial distribution with μ =250 and 𝜎 =11.18. What is the
minimum usual value?
238.82
227.64
261.18
327.64
9-If the table below is probability distribution of random variable X. What is the value of k?
Sale price in thousand $ (X)
10
20
30
40
Probability p(X)
0.3
0.5
0.1
k
0.2
1.0
0.9
0.1
10-The scores on a recent statistics test are given in the frequency distribution below. What is the
relative frequency corresponding to the class 81-90?
Scores
Frequency
0-60
2
61-70
8
71-80
10
81-90
6
91-100
4
0.20
0.40
0.10
0.30
11-Stem plot of the following data 46, 65, 55, 43, 51, 48, 57, 30, 43, 49, 32, 56 is
3
02
4
3 689
5
1560
6
51
3
12
4
3 689
5
1560
6
51
3
02
4
33689
5
1567
6
5
3
02
4
3 689
4
13567
6
5
12-If the relative frequencies of class-intervals of a distribution are 0.20, 0.10, x, 0.25 & 0.15.
Then the value of the missing value x is
0.25
0.15
0.30
0.20
13-The temperatue of a cup of coffee is 65 oF. The given value is from a continuous data.
True
False
14-The total number of phone calls a sales representative makes in a month represents a discrete
data.
True
False
15-The midterm marks obtained by 4 students in a sample are as follows: 17, 24, 18, and 21.
What is the variance of this data.
10
6
20
3.16
16-A student had the following grades in the related courses:
Course
Mathematics
English language
PE
Weight
6
4
2
Grade
70
65
92
Given the weights of the courses, the weighted mean grade of the student is:
864
75.67
72
288
17-Listed below are the amounts of time (in months) that the employees of a restaurant have
been working at the restaurant. What is the median of this data?
22, 11, 55, 33, 99, 66
44 months
33 months
22 months
55 months
18-At one college, GPA’s are normally distributed with a mean of 2.6 and a standard deviation
of 0.4. According to empirical rule, What percentage of students at the college have a GPA
between 1.8 and 3.4?
99.7%
68%
95%
84.13%
19-Which type of sampling is used in the statement, ‘On the day of the last presidential election,
ABC News organized an exit poll in which specific polling stations were randomly selected and
all voters were surveyed as they left the premises.’
Convenience
Systematic
Stratified
Cluster
20-A firm uses trend projection and seasonal factors to simulate sales for a given time period. It
assigns “0” if sales fall, “1” if sales are steady, “2” if sales rise moderately and “3” if sales rise a
lot. The simulator generates the following output:
0 1 1 0 0 2 1 0 2 3
What is the probability that sales will fall?
0.30
0.20
0.40
0.10
21-A card is selected at random from a pack of 52 cards. What is the probability that the card is
either an ace or red color?
7/13
0
3/13
1/13
22-A box of 600 bulbs contains 12 defective bulbs. One bulb is taken out at random from this
box. Then the probability that it is non-defective bulb is
1/50
1/125
147/150
123/150