Question

Your friend states in a report that the average time required to circle a 1.5-mi track was 65.414 s. This was measured by timing 7 laps using a clock with a precision of 0.1 s. How much confidence do you have in the results of the report? Explain.

Answer 1

The time per lap was calculated by measuring the time for seven laps and dividing the total time by seven.

total time $65.414 s \times 7 =457.898 s.$

It is given that the precision is of 0.1 s. it means it is correct upto 1 place beyond decimal.

So, the actual value could vary from 457.800 s to 457.899 s i.e. the time per lap could be 65.400 s to 65.414 s

It means measured time 65.414 s has maximum error of 0.021%. Hence, the measured value is quite precise.