Question

The reading on a car’s speedometer may have an error up to 6.25%. The speed limit on a road is 65 miles per hour.

The speedometer shows 67 miles per hour.

Is the car definitely going over the speed limit?
Yes
No
Explain your thinking.

Answer 1

No.
The speed limit is 65. Accounting for a 6.25% error, then there is a range of speeds that could be considered 65.
The range:
65(0.9375) = 60.9375
65(1.0625) = 69.0625
So, any speed within that range is within the error zone. Therefore, a reading of 67 is not necessarily speeding.

Answer 2

I’m thinking no .....