Reading Data and Graphs: Additional Practice (Set 1)

Read the two Week 1 bars. Shop A is $8$ and Shop B is $4$.

$8 - 4 = 4$

Compare the paired bars within the same week.

Red is $40\%$ of the $200$ votes.

$\frac{40}{100} \times 200 = 80$

A flat segment means no change. The segment from February to March stays level at $40$.

$40 \to 40 \text{ (no change)}$

Every other segment rises or falls.

Saturday shows $4$ whole circles and one half circle, which is $4.5$ symbols. Multiply by the key of $6$.

$4.5 \times 6 = 27$

The half circle adds $3$ pizzas.

A circle graph splits one whole into parts at a single moment. It has no time axis.

$\text{change over time} \;\Rightarrow\; \text{line graph, not circle graph}$

To show change over the year you would use a line graph instead.

Convert each row with the key, then subtract. First row $6 \times 5 = 30$; second row $4 \times 5 = 20$.

$30 - 20 = 10$

You could also note the rows differ by $2$ symbols, and $2 \times 5 = 10$.

Look only at the Shop B bars (the accent color): $4$, $8$, $6$.

$\text{Shop B: } 4,\; 8,\; 6 \;\Rightarrow\; \text{most in Week 2}$

Net change compares only the first and last points. January is $20$ and May is $50$.

$50 - 20 = 30$

The frequencies add to the total, so subtract the known counts from $20$.

$20 - 6 - 9 = 5$

With the axis starting at $90$, only the part of each value above $90$ is drawn, so a doubled height is not a doubled value.

$\text{cut-off axis} \;\Rightarrow\; \text{height ratio} \ne \text{value ratio}$

Read the actual numbers off the scale instead.

Multiply the slice's percent by the total.

$\frac{30}{100} \times 50 = 0.3 \times 50 = 15$

Add the three Shop A bars (the base color): $8$, $6$, $10$.

$8 + 6 + 10 = 24$