Let's use the formula: distance = rate x time
During the snowstorm, Paul drove for a certain amount of time, let's call it t.
Then, his distance traveled during the snowstorm would be:
distance1 = rate1 x t
After the snow stopped, Paul increased his speed by 30 mph and drove for 4 - t hours (since he drove for a total of 4 hours and spent t hours driving in the snowstorm).
Then, his distance traveled after the snowstorm would be:
distance2 = rate2 x (4 - t)
We know that in total, Paul traveled 40 + 132 = 172 miles. So, we can set up an equation:
distance1 + distance2 = total distance
rate1 x t + rate2 x (4 - t) = 172
Now, we can solve for Paul's average rate of speed (x) during the snowstorm:
rate1 = x
rate2 = x + 30
x(t) + (x + 30)(4 - t) = 172
Simplifying:
xt + 120 - xt + 30t = 172
Combining like terms:
30t + 120 = 172
Subtracting 120 from both sides:
30t = 52
Dividing by 30:
t = 1.73 hours
Now we can substitute t back into one of the equations we derived earlier:
distance1 = x(1.73)
distance2 = (x + 30)(2.27)
We know that distance1 + distance2 = 172:
x(1.73) + (x + 30)(2.27) = 172
Expanding:
1.73x + 2.27x + 68.1 = 172
Combining like terms:
4x = 103.9
Dividing by 4:
x = 25.98 mph
Therefore, Paul's average rate of speed during the snowstorm was approximately 26 mph.