School of Mathematics and Statistics
Junior
The University of Sydney
spcr

Quiz 1: Data sets

Last unanswered question  Question  Next unanswered question
 

Question 1

 
 
Questions 1-8 use the same data.
 
The following integers were obtained as the number of visits to a gift shop, per hour, over several days.
 
0,2,3,1,2,4,5,2,3,4,
2,3,3,5,6,2,1,4,1,4,
3,1,6,2,1,4,5,2,3,3,
1,2.
 
Find the mean of the above data, to 2 decimal places.
a) 2.80   b) 3.00
c) 2.81   d) 2.8

 

Not correct. Choice (a) is false.
Not correct. Choice (b) is false.
Your answer is correct.
Not correct. Choice (d) is false.
 

Question 2

 
 
Questions 1-8 use the same data.
 
The following integers were obtained as the number of visits to a gift shop, per hour, over several days.
 
0,2,3,1,2,4,5,2,3,4,
2,3,3,5,6,2,1,4,1,4,
3,1,6,2,1,4,5,2,3,3,
1,2.
 
Find the median of the above data.
a) 3   b) 2
c) 2.5   d) 3.5

 

Your answer is correct.
Since n = 32, the median is the average of the 16th and 17th entries which is 3.
Not correct. Choice (b) is false.
Not correct. Choice (c) is false.
Not correct. Choice (d) is false.
 

Question 3

 
 
Questions 1-8 use the same data.
 
The following integers were obtained as the number of visits to a gift shop, per hour, over several days.
 
0,2,3,1,2,4,5,2,3,4,
2,3,3,5,6,2,1,4,1,4,
3,1,6,2,1,4,5,2,3,3,
1,2.
 
Find the upper quartile of the above data.
a) 4.5   b) 3.5
c) 4   d) 2

 

Not correct. Choice (a) is false.
Not correct. Choice (b) is false.
Your answer is correct.
Since n = 32, the upper quartile is the average of the 24th and 25th entries, which is 4.
Not correct. Choice (d) is false.
 

Question 4

 
 
Questions 1-8 use the same data.
 
The following integers were obtained as the number of visits to a gift shop, per hour, over several days.
 
0,2,3,1,2,4,5,2,3,4,
2,3,3,5,6,2,1,4,1,4,
3,1,6,2,1,4,5,2,3,3,
1,2.
 
Find the lower quartile of the above data.
a) 2   b) 3
c) 1   d) 1.5

 

Your answer is correct.
Since n = 32, the lower quartile is the average of the 8th and 9th entries which is 2.
Not correct. Choice (b) is false.
Not correct. Choice (c) is false.
Not correct. Choice (d) is false.
 

Question 5

 
 
Questions 1-8 use the same data.
 
The following integers were obtained as the number of visits to a gift shop, per hour, over several days.
 
0,2,3,1,2,4,5,2,3,4,
2,3,3,5,6,2,1,4,1,4,
3,1,6,2,1,4,5,2,3,3,
1,2.
 
Find the interquartile range.
a) 3   b) 2
c) 1.5   d) 2.5

 

Not correct. Choice (a) is false.
Your answer is correct.
IQR  = UQ  - LQ  = 4 - 2 = 2.
Not correct. Choice (c) is false.
Not correct. Choice (d) is false.
 

Question 6

 
 
Questions 1-8 use the same data.
 
The following integers were obtained as the number of visits to a gift shop, per hour, over several days.
 
0,2,3,1,2,4,5,2,3,4,
2,3,3,5,6,2,1,4,1,4,
3,1,6,2,1,4,5,2,3,3,
1,2.
 
Find the upper threshold for the above data.
a) 7   b) 6
c) 5.5   d) 4.5

 

Your answer is correct.
UT  = UQ  + 1.5 * IQR  = 4 + 1.5 * 2 = 7.
Not correct. Choice (b) is false.
Not correct. Choice (c) is false.
Not correct. Choice (d) is false.
 

Question 7

 
 
Questions 1-8 use the same data.
 
The following integers were obtained as the number of visits to a gift shop, per hour, over several days.
 
0,2,3,1,2,4,5,2,3,4,
2,3,3,5,6,2,1,4,1,4,
3,1,6,2,1,4,5,2,3,3,
1,2.
 
Find the lower threshold for the above data.
a) 0.5   b) 1
c) -1   d) 0

 

Not correct. Choice (a) is false.
Not correct. Choice (b) is false.
Your answer is correct.
LT  = LQ  - 1.5 * IQR  = 2 - 1.5 * 2 = -1.
Not correct. Choice (d) is false.
 

Question 8

 
 
Questions 1-8 use the same data.
 
The following integers were obtained as the number of visits to a gift shop, per hour, over several days.
 
0,2,3,1,2,4,5,2,3,4,
2,3,3,5,6,2,1,4,1,4,
3,1,6,2,1,4,5,2,3,3,
1,2.
 
Find the outlier(s) for the above data.
a) There are no outlier(s).   b) 0
c) 6   d) -1

 

Your answer is correct.
All of the data points lie between -1 and 7 inclusive, so there are no outliers.
Not correct. Choice (b) is false.
Not correct. Choice (c) is false.
Not correct. Choice (d) is false.
 

Question 9

 
 
The 5-figure summary of a sample of data is:

88.6    90.4    91.6    92.7   94.7

What is the interquartile range (IQR)?

 

Your answer is correct
Q3 = 92.7 and Q1 = 90.4 so IQR= 92.7 - 90.4 = 2.3.
Not correct. You may try again.
Which figures in the summary are the first and third quartiles?
 

Question 10

 
 
The following measurements (in mm) were taken (to a very high degree of accuracy) for the expansion of sections of railway track on days when the temperature exceeded 35oC. They were distributed into the following intervals, with the indicated frequencies.
 
Cell boundary Frequency
0 to <0.1      3
0.1 to <0.2      5
0.2 to <0.3       10
0.3 to <0.4      8
0.4 to <0.5       6
0.5 to <0.6       4
0.6 to <0.7       3
0.7 to <0.8      2
 
How would you describe the above distribution?
a) Left skewed.   b) Right skewed.
c) Symmetrical.   d) Uniform.

 

Not correct. Choice (a) is false.
Your answer is correct.
The distribution has a long right tail.
Not correct. Choice (c) is false.
Not correct. Choice (d) is false.