To determine the percentage of winning average speeds between 160-169.9 miles per hour that were achieved by Chevrolets, follow these steps:
1. Identify the number of wins by Chevrolets in the 160-169.9 mph range:
From the table, the number of wins by Chevrolets in the 160-169.9 mph range is 75.
2. Identify the total number of wins in the 160-169.9 mph range:
From the table, the total number of wins in the 160-169.9 mph range is 100.
3. Calculate the percentage of wins by Chevrolets:
To find the percentage, divide the number of wins by Chevrolets by the total number of wins in this range and then multiply by 100 to convert it to a percentage.
[tex]\[
\text{Percentage of Chevrolet wins} = \left(\frac{\text{Chevrolet wins}}{\text{Total wins}}\right) \times 100
\][/tex]
Substituting the given numbers:
[tex]\[
\text{Percentage of Chevrolet wins} = \left(\frac{75}{100}\right) \times 100
\][/tex]
4. Perform the calculation:
[tex]\[
\left(\frac{75}{100}\right) \times 100 = 75
\][/tex]
Therefore, the percentage of winning average speeds between 160-169.9 miles per hour that were Chevrolets is:
[tex]\[
75 \%
\][/tex]