Question

a recent study observed the number of bike riders ages 0 to 20 that wear helmets. the results are represented in the table.

	wear helmet	did not wear helmet
6-10 years	34	14
11-15 years	14	18
16-20 years	3	12

make an observation based on a data value that is not in the table. explain your reasoning.

Explanation:

To make an observation, we can calculate the total number of bike riders in each age group (by adding "Wear Helmet" and "Did Not Wear Helmet" counts) or the overall total, or calculate proportions (e.g., percentage of helmet - wearers in each group). For example, let's calculate the total number of bike riders in each age group:

• For 0 - 5 years: \(21 + 4=25\)
• For 6 - 10 years: \(34 + 14 = 48\)
• For 11 - 15 years: \(14+18 = 32\)
• For 16 - 20 years: \(3 + 12=15\)

Now, let's calculate the percentage of helmet - wearers in each group:

• 0 - 5 years: \(\frac{21}{25}\times100\% = 84\%\)
• 6 - 10 years: \(\frac{34}{48}\times100\%\approx70.83\%\)
• 11 - 15 years: \(\frac{14}{32}\times100\% = 43.75\%\)
• 16 - 20 years: \(\frac{3}{15}\times100\%=20\%\)

An observation could be: As the age of bike riders increases from 0 - 5 years to 16 - 20 years, the percentage of bike riders who wear helmets decreases. This is evident from the calculated percentages: 84% (0 - 5), ~70.83% (6 - 10), 43.75% (11 - 15), and 20% (16 - 20). The decrease in the percentage of helmet - wearers with increasing age might be due to a variety of factors such as changing attitudes towards safety, peer influence, or less parental supervision as children get older.

Answer:

As the age of bike riders increases from 0 - 5 years to 16 - 20 years, the percentage of bike riders who wear helmets decreases (e.g., 84% for 0 - 5, ~70.83% for 6 - 10, 43.75% for 11 - 15, 20% for 16 - 20), likely due to factors like changing attitudes and less supervision.