Knewton Alta -Chapter 2- Descriptive
Statistics Part 1
relative frequency - ANSWER-is the ratio (fraction or proportion) of the number of times a
certain data value occurs in the set of the total number of data values.
To find the relative frequencies, divide each frequency by the total number of data values in
the sample. Relative frequencies can be written as fractions, percents, or decimals.
Relative frequency table - ANSWER-a frequency table with an additional column giving the
relative frequencies of the dataInstead of a Relative frequency table, some sources may give
this information in the form of a Relative frequency histogram
Frequency of a class - ANSWER-The frequency of a class is the product of the total number of
data values and the relative frequency of the class.
What is the cumulative relative frequency of students that went to 5 or fewer movies? -
ANSWER-0.05+0.23+0.27= 0.55
0.55
A data set is summarized in the frequency table below. Using the table, determine the
number of values greater than or equal to 8. Give your answer as a single number. For
example if you found the number of values was 33, you would enter 33. - ANSWER-
4+6+8+4+5=27
The ages of the students in a creative writing seminar are listed below.
17,22,20,18,19,20,17,17,22,18,20,18,17,18,21,18,18,19,19,19,20,19,21,21
Complete the frequency table. - ANSWER-The age 17 appears 4 times.
The age 18 appears 6 times.
The age 19 appears 5 times.
,The age 20 appears 4 times.
The age 21 appears 3 times.
The age 22 appears 2 times.
A data set is summarized in the frequency table below. Using the table, determine the
number of data values less than or equal to 5. Give your answer as a single number. For
example if you found the number of values was 19, you would enter 19.
VF
39
44
53
67
76
83
93
10 5
11 4 - ANSWER-To find the number of data values less than or equal to 5, we add the
frequencies for the values 3, 4, and 5. The relevant values are highlighted in the table below.
Summing the frequencies for these values, we find
9+4+3=16
A data set is summarized in the frequency table below. Using the table, determine the total
number of values in the data set that are less than or equal to 7.
V-F
3-8
4-4
5-3
6-2
7-2
8-7
9-3
10 - 6
, 11 - 3
12 - 7 - ANSWER-19
Summing the frequencies for these values, we find
8+4+3+2+2=19
A data set is summarized in the frequency table below. The data set contains a total of 40
data values. What is the missing frequency?
V-F
1-4
2-6
3-7
4-3
5 - ___
6-5
7-4
8 - 5 - ANSWER-The total number of data values is the sum of all the frequencies. We are
told the data set contains a total of 40 data values.
The seven given values add to 4+6+7+3+5+4+5=34, so the missing frequency is 40−34=6.
The relative frequencies for a set of data are shown in the table below.
V - RF
1 - 0.15
2 - 0.10
3 - 0.45
4 - 0.30
If there are a total of 20 data values, with what frequency does the data value 3 occur? -
ANSWER-Dividing each frequency by the total number of data values gives the relative
frequency. So multiplying the relative frequency by the total number of data values gives the
frequency.
Statistics Part 1
relative frequency - ANSWER-is the ratio (fraction or proportion) of the number of times a
certain data value occurs in the set of the total number of data values.
To find the relative frequencies, divide each frequency by the total number of data values in
the sample. Relative frequencies can be written as fractions, percents, or decimals.
Relative frequency table - ANSWER-a frequency table with an additional column giving the
relative frequencies of the dataInstead of a Relative frequency table, some sources may give
this information in the form of a Relative frequency histogram
Frequency of a class - ANSWER-The frequency of a class is the product of the total number of
data values and the relative frequency of the class.
What is the cumulative relative frequency of students that went to 5 or fewer movies? -
ANSWER-0.05+0.23+0.27= 0.55
0.55
A data set is summarized in the frequency table below. Using the table, determine the
number of values greater than or equal to 8. Give your answer as a single number. For
example if you found the number of values was 33, you would enter 33. - ANSWER-
4+6+8+4+5=27
The ages of the students in a creative writing seminar are listed below.
17,22,20,18,19,20,17,17,22,18,20,18,17,18,21,18,18,19,19,19,20,19,21,21
Complete the frequency table. - ANSWER-The age 17 appears 4 times.
The age 18 appears 6 times.
The age 19 appears 5 times.
,The age 20 appears 4 times.
The age 21 appears 3 times.
The age 22 appears 2 times.
A data set is summarized in the frequency table below. Using the table, determine the
number of data values less than or equal to 5. Give your answer as a single number. For
example if you found the number of values was 19, you would enter 19.
VF
39
44
53
67
76
83
93
10 5
11 4 - ANSWER-To find the number of data values less than or equal to 5, we add the
frequencies for the values 3, 4, and 5. The relevant values are highlighted in the table below.
Summing the frequencies for these values, we find
9+4+3=16
A data set is summarized in the frequency table below. Using the table, determine the total
number of values in the data set that are less than or equal to 7.
V-F
3-8
4-4
5-3
6-2
7-2
8-7
9-3
10 - 6
, 11 - 3
12 - 7 - ANSWER-19
Summing the frequencies for these values, we find
8+4+3+2+2=19
A data set is summarized in the frequency table below. The data set contains a total of 40
data values. What is the missing frequency?
V-F
1-4
2-6
3-7
4-3
5 - ___
6-5
7-4
8 - 5 - ANSWER-The total number of data values is the sum of all the frequencies. We are
told the data set contains a total of 40 data values.
The seven given values add to 4+6+7+3+5+4+5=34, so the missing frequency is 40−34=6.
The relative frequencies for a set of data are shown in the table below.
V - RF
1 - 0.15
2 - 0.10
3 - 0.45
4 - 0.30
If there are a total of 20 data values, with what frequency does the data value 3 occur? -
ANSWER-Dividing each frequency by the total number of data values gives the relative
frequency. So multiplying the relative frequency by the total number of data values gives the
frequency.
