Please help! Will give fan and medal.
A set of data has a normal distribution with a mean of 47 and a standard deviation of 9. Find the percent of data within the following interval. From 20 to 74.

The percent of data within the given interval is ___%

Thank you in advance!

Question

Please help! Will give fan and medal.
A set of data has a normal distribution with a mean of 47 and a standard deviation of 9. Find the percent of data within the following interval. From 20 to 74.

The percent of data within the given interval is ___%

Thank you in advance!

misty1212 · Answer

HI!! you can use this but it will take two steps http://stattrek.com/online-calculator/normal.aspx

misty1212 · Answer

put in 47 for the mean, 9 for the standard deviation, and 20 for the normal random variable

ray1998 · Answer

Hi! Okay, thank you so much!! What would I put in for the probability?

misty1212 · Answer

you get $$P(x<20)=.00135$$ 
then to it again using 74 for the random variab,le

misty1212 · Answer

subtract $.00135$  from what you get for $x=74$

misty1212 · Answer

hope it is clear
leave the $P(X\leq x)$ blank that is what you are looking for

ray1998 · Answer

So, 0.00135 - 0.99865= -0.9973?

misty1212 · Answer

other way around

ray1998 · Answer

Oh, alright

misty1212 · Answer

or just take your answer and make it positive

ray1998 · Answer

Alrighty :) thank you so much! Are there any other steps?

misty1212 · Answer

nope that is it unless you have to convert it to a percent

misty1212 · Answer

oh yeah you do

misty1212 · Answer

$$99.73\%$$

ray1998 · Answer

Alrighty, thank you very much!!!