simpatique
Well-known member
- Joined
- Apr 30, 2010
- Messages
- 98
- Reaction score
- 1
I ran across a problem regarding spot speed ( answer not verified ) . Can you show how to solve it? Thank you
Consider the following two spot speed samples conducted a test location to determine the
effectiveness of a new speed limit posting at 50mph.
Before After
Average Speed 55.3mph 52.8mph
Standard Deviation 5.0mph 5.6mph
Sample Size 100 85
a. Was the new speed limit effective in reducing average speeds at this location?
b. Was the new speed limit effective in reducing average speeds to 50mph?
I tried to use the Z test as I understood it but I am getting Z < 0 so I know I am doing something wrong here .
I'd appreciate your help
Consider the following two spot speed samples conducted a test location to determine the
effectiveness of a new speed limit posting at 50mph.
Before After
Average Speed 55.3mph 52.8mph
Standard Deviation 5.0mph 5.6mph
Sample Size 100 85
a. Was the new speed limit effective in reducing average speeds at this location?
b. Was the new speed limit effective in reducing average speeds to 50mph?
I tried to use the Z test as I understood it but I am getting Z < 0 so I know I am doing something wrong here .
I'd appreciate your help