Question

fan and medal !!
a normal distribution has a mean of 64 and a standard deviation of 7. use the standard normal table to find the indicated probability for a randomly selected x-value from the distribution
p(x<68)
p(x<80)
p(x<45)

Answer 1

would you like help

Answer 2

yes please @perl

Answer 3

determine the zscore, and use that to look up the table value.

Answer 4

the zscore is the number of standard deviations x is from the mean.

so subtract the mean from your x value, and divide by the standard deviation to see how many there are:

\[z=\frac{x-mean}{sd}\]
this value is usually tabled and you cross row and column to determine the answer in the feild