Final answer:
To find the expected number of vehicles passing in two minutes, convert the hourly rate to a per-minute rate and multiply by two. For an average rate of 99 vehicles per hour, we would expect approximately 3 or 4 vehicles to pass in two minutes.
Step-by-step explanation:
If vehicles pass through a junction at an average rate of 99 per hour, we need to calculate how many would be expected to pass in two minutes. First, we have to convert the hourly rate into a rate per minute. Since there are 60 minutes in an hour, we divide 99 by 60, which gives us 1.65 vehicles per minute. Therefore, in two minutes, we would expect 1.65 vehicles x 2 minutes = 3.3 vehicles. As the number of vehicles cannot be a decimal, we would expect either 3 or 4 vehicles to pass in two minutes, depending on the specific situation and rounding method used.