hi there,

could anyone help me out? i really don't understandz-scores... i have a final coming up and i can't contact my teachers because they are all on holidays.

for a given question, do i use the formula: z=(x-mean)/(standard deviation)? because when i am given the values for x, the mean, and standard deviation to findz,i always end up with a negative number or something that doesn't seem right. For example,

x= 20

Mean = 45

Standard Deviation = 12

How do I find the z-score using these values? It can't be just plugging the values into the formula. How do I use the chart? As well, what if I am not given anxvalues? What do I do?

thanks.