http://www.ck12.org Chapter 5. Measures of Central Tendency
Guided Practice
The following data shows the heights in centimeters of a group of grade 10 students:
183 171 158 171 182 158 164 183
179 170 182 183 170 171 167 176
176 164 176 179 183 176 170 183
183 167 167 176 171 182 179 170
Organize the data in a frequency distribution table and calculate the mean height of the students.
Answer:
The data can be organized into a frequency distribution table as shown below:
TABLE5.4:
Height of Students(cm) Tally Number of Students (Frequency)
171 |||| 4
158 || 2(^176) |||| 5
182 ||| 3
164 || 2
179 ||| 3
170 |||| 4
(^183) ||||| 6
167 ||| 3
Now the frequency distribution table can be used to calculate the mean as follows:
x=∑
x 1 f 1 +x 2 f 2 +x 3 f 3 +...+xnfn
f 1 +f 2 +f 3 +...+fn
x=
∑(^171 )(^4 )+(^158 )(^2 )+(^176 )(^5 )+(^182 )(^3 )+(^164 )(^2 )+(^179 )(^3 )+(^170 )(^4 )+(^183 )(^6 )+(^167 )(^3 )
4 + 2 + 5 + 3 + 2 + 3 + 4 + 6 + 3
x=∑ 684 + 316 + 880 + 546 + 328 + 537 + 680 + 1098 + 501
32
x=5570
32
≈ 174 .1 cmThe mean height of the students is approximately 174.1 cm.