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

Answer:

d.  1.5%

Step-by-step 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 = $\frac{60 - 63}{63}. 100$%

                                                                           = $-\frac{3}{63}.100$% = - 4.761904762 %

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

Now,

% change from Practice 2 to Practice 3 change = $\frac{58 - 60}{60}. 100$%

                                                                           = $-\frac{2}{60}.100$% = - 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%