MAT 131 Unit 1 Questions with Verified Correct
Answer
A teacher returns an exam with possible scores ranging from 0 to 100. The students suspect
that the majority of them performed poorly on the exam and request summary statistics.
The teacher provides the mean, which was 72, as a summary statistic. A total of 400
students took the exam. The teacher, after several requests, provides a boxplot of the exam
scores. The students can get which of the following pieces of information from this plot?
All of the answer options are correct.
The exam scores (out of 100 points) for all students taking an introductory statistics course
are used to construct the following boxplot: Based on this boxplot, the interquartile range is
closest to:
25
The graph below shows a distribution that is called a chi-squared distribution. For this
distribution, the median:
is smaller than the mean.
A poll was conducted of more than 50,000 buyers of new cars, 90 days after the cars were
purchased. The data on problems per 100 vehicles for cars made by Toyota and General
Motors (GM) are given in the time plot below for the years 1998-2004. The solid line is for
GM and the dashed line is for Toyota. In 2002, the number of problems per 100 vehicles
was:
about 20% higher for GM than for Toyota.
, Birth weights at a local hospital have a Normal distribution, with a mean of 110 oz and a
standard deviation of 12 oz. The proportion of infants with birth weights above 125 oz is:
0.106
A violin student records the number of hours she spends practicing during each of nine
consecutive weeks:
6.2
5.0
4.3
7.4
5.8
7.2
8.4
1.2
6.3
What is the first quartile for these data?
4.65 hours
A survey of 10 students was conducted to investigate the amount of time they spend on
social media each day. Students were given a timer and asked to record the number of
minutes spent every time they accessed social media. The students' total times for one day
are given below (in minutes). 45 57 63 79 84 92 99 105 117 145
The standard deviation for these data is:
Answer
A teacher returns an exam with possible scores ranging from 0 to 100. The students suspect
that the majority of them performed poorly on the exam and request summary statistics.
The teacher provides the mean, which was 72, as a summary statistic. A total of 400
students took the exam. The teacher, after several requests, provides a boxplot of the exam
scores. The students can get which of the following pieces of information from this plot?
All of the answer options are correct.
The exam scores (out of 100 points) for all students taking an introductory statistics course
are used to construct the following boxplot: Based on this boxplot, the interquartile range is
closest to:
25
The graph below shows a distribution that is called a chi-squared distribution. For this
distribution, the median:
is smaller than the mean.
A poll was conducted of more than 50,000 buyers of new cars, 90 days after the cars were
purchased. The data on problems per 100 vehicles for cars made by Toyota and General
Motors (GM) are given in the time plot below for the years 1998-2004. The solid line is for
GM and the dashed line is for Toyota. In 2002, the number of problems per 100 vehicles
was:
about 20% higher for GM than for Toyota.
, Birth weights at a local hospital have a Normal distribution, with a mean of 110 oz and a
standard deviation of 12 oz. The proportion of infants with birth weights above 125 oz is:
0.106
A violin student records the number of hours she spends practicing during each of nine
consecutive weeks:
6.2
5.0
4.3
7.4
5.8
7.2
8.4
1.2
6.3
What is the first quartile for these data?
4.65 hours
A survey of 10 students was conducted to investigate the amount of time they spend on
social media each day. Students were given a timer and asked to record the number of
minutes spent every time they accessed social media. The students' total times for one day
are given below (in minutes). 45 57 63 79 84 92 99 105 117 145
The standard deviation for these data is:
