What is the relationship between Z-scores and probability?

[yourneighbours]

On average, 99% of the people were between ___ and ___kilometers away from their home when they got
into an accident
the mean is 30 with a standard deviation of 8

 

[MarkFL]

Hello and welcome to MHB! :D

Did you mean to use the [SOLVED] prefix for your thread? When you use this, people assume you don't need help.

So, given the symmetry of normally distributed data about the mean, we know we want to eliminate the lower and upper 0.5% of the data.

So, what area do we want associated from the mean to the upper limit?

 

[Jameson]

Another way of thinking about what Mark is suggesting is to remember the rule for going 1,2 and 3 standard deviations away from the mean in both directions. 1 SD both ways covers about 68%, 2 covers ______ and 3 covers _______. Have you seen this before?