Question

jim measured the daily rainfall in mm at the same spot in his garden for each day in the year (365 days). he recorded his results to the nearest millimeter. the results are shown in the following histogram: histogram description with no. of days on y - axis and rainfall (mm) on x - axis. on approximately what percent of the days was the rainfall more than 15 mm? a approximately 10% b approximately 20% c approximately 30% d approximately 40%

Explanation:

Step1: Count days with > 15mm rainfall

Count the heights of bars for rainfall intervals 15 - 20mm, 20 - 25mm and 25 - 30mm. Assume values from the histogram: 50 (for 15 - 20mm), 25 (for 20 - 25mm) and 10 (for 25 - 30mm). Total days with > 15mm rainfall is $50 + 25+10=85$.

Step2: Calculate total days

Total number of days is 365.

Step3: Calculate percentage

Use the formula $\text{Percentage}=\frac{\text{Days with > 15mm rainfall}}{\text{Total days}}\times100\%$. So $\text{Percentage}=\frac{85}{365}\times 100\%\approx 23.3\%$.

Answer:

B. Approximately 20%