Question

The track and field coach records Ian's 400-meter race times during three practices. How much greater was the percent of change from Practice 1 to Practice 2 than from Practice 2 to Practice 3? Round to the nearest tenth.

Answer 1

d. 1.5%

Explanation:

Given - The track and field coach records Ian's 400-meter race times during three practices.

Practice 1 2 3

Time (s) 63 60 58

To find - How much greater was the percent of change from Practice 1 to Practice 2 than from Practice 2 to Practice 3? Round to the nearest tenth.

a. 7.9%

b. 4.8%

c. 3.3%

d. 1.5%

Proof -

% change from Practice 1 to Practice 2 change =
`(60 - 63)/(63). 100`%

=
`-(3)/(63).100`% = - 4.761904762 %

⇒% change from Practice 1 to Practice 2 change = - 4.762 %

Now,

% change from Practice 2 to Practice 3 change =
`(58 - 60)/(60). 100`%

=
`-(2)/(60).100`% = - 3.334 %

⇒% change from Practice 2 to Practice 3 change = - 3.3334 %

So,

- 4.461904762% - (- 3.3334%) = -4.461904762 + 3.3334 % = -1.4285 % ≈ 1.5%

∴ we get

Value = 1.5%

The correct option is - d. 1.5%