Question

Lucia ran the 400-meter race 3 times. Her fastest time was 52.2 seconds. Her slowest time was 56.3 seconds. If Luzia’s average time was 54.0 seconds, what was time for the third race?

Answer 1

53.5 sec

Explanation:

Given

Number of times Lucia ran the race=n=3

Slowest time= x_1=56.3 sec

Fastest Time= x_2=52.2 sec

Average time=54.0 sec

Since, we know the average time and two of the three race times, we can use the average formula to calculate the third race’s time.

Let

x_3=the third race^' s time

So,

Average=(Sum of values)/(Number of values)

Average = (x_1+ x_2+ x_3)/n

Putting the values

54.0= (56.3+ 52.2+ x_3)/3

Multiplying 3 with 54.0 and adding 56.3 and 52.2

162= 56.3+52.2+ x_3

162= 108.5+ x_3

x_(3 )=162-108.5

x_(3 )=53.5 sec

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