While taking the reading from a test tube( or cross section of a graduated cylinder) we note the value at lower meniscus. We should also keep in mind at the time of reading, our hand should be stable(to minimize human error) and at this stable condition lower meniscus would the the right reading.
Then, divide the sum by two. This will give you the average speed for the entire trip. So, if Ben traveled 40 mph for 2 hours, then 60 mph for another 2 hours, his average speed is 50 mph.
