Page 171 - Math Smart - 7

Tony measured the size of 22 angles.

15° 16° 9° 21° 32° 37° 25° 36° 40° 8° 32°
13° 21° 32° 29° 32° 29° 32° 7° 4° 18° 17°

Construct a frequency table to organise this data. Use four equal class intervals.

Range of angle ° Tally Frequency

Total
® The points scored in a shooting competition are recorded.

18 24 19 3 24 11 25 10 25 14 25 14 25 9
16 26 21 27 13 23 5 26 22 12 27 20 7 28
21 20 22 16 12 25 7 25 19 17 15 8

a) Construct a frequency table using the class intervals 1-5, 6-10, 11-15, 16-20, 21-25 and 26-30.
b) Use the same data to construct a frequency table with ten class intervals.
c) Which frequency table is better? Give a reason for your answer.

Spotlight

^^OUNTIF(C2:C10,"*ed"
Computer software
such as Excel can
generate frequency
tables by counting the Product n Status D \
cells that contains a
Product 1 Destination Scan 3l
particular text.
1 Product 2 Delivered
Product 3 Arrival Scan
Product 4 Destination Scan
1 Product 4 Delivered
1 Product 5 In Transit
1 Product 6 Received
Product 7 In Transit
Figure 7.1 Example of a frequency table in Excel
Spreadsheet using a 'countif function. The instruction
given to the software is to count the number of cells
with words ending with 'ed'.