Data & Graphs

Depth · one concept from first principles · step 2 of 4

Convert a pictograph into a frequency table

Ms. Reed's class and Mr. Diaz's class were each surveyed about which mountain they want to visit, and the results are shown in the tables below. If the two classes go on the field trip together, which mountain should they choose?

Ms. Reed's class

Mountain Pine Ridge Eagle Peak Mount Rainier Cedar Butte Total
Students 5 8 7 3 23

Mr. Diaz's class

Mountain Pine Ridge Eagle Peak Mount Rainier Cedar Butte Total
Students 6 4 9 5 24
Measurement & data
Your answer
How to solve
Strategy Organize Information in More Ways — Merging the two separate tables into one combined frequency table (re-organizing the data) lets us compare totals. Listing each mountain's combined count makes the largest easy to spot.
1STEP 1

Add each mountain across both classes

For each mountain, add Ms. Reed's count and Mr. Diaz's count: Pine Ridge 5+6=11, Eagle Peak 8+4=12, Mount Rainier 7+9=16, Cedar Butte 3+5=8.

5+6=11, 8+4=12, 7+9=16, 3+5=8
2STEP 2

Check the total

The combined votes should equal 23 + 24 = 47. Indeed 11 + 12 + 16 + 8 = 47, so no votes were lost.

11+12+16+8 = 47 = 23+24
3STEP 3

Pick the largest

The biggest combined count is 16 for Mount Rainier, more than Eagle Peak's 12, Pine Ridge's 11, and Cedar Butte's 8.

16 ＞ 12 ＞ 11 ＞ 8
Answer
Mount Rainier (16 votes combined)
Mount Rainier wins in Mr. Diaz's class (9) and is second in Ms. Reed's class (7), so its leading combined total of 16 is sensible. All four totals sum to 47, matching 23+24, so the data is accounted for.
Takeaway

Stack the two tables into one and find the tallest count - that's Grade 3 graph reading!

  • Add each mountain across both classes
  • Check the total
  • Pick the largest
Where next?
Level upsuggested
Read a double bar graphFind the value of one grid square
Another one like thissuggested
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Step back and solidifysuggested
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