# Normally Distributed Data w/ mean of 16, standard dev. of...

#### Jen123

##### New member
Question: A set of data is normally distributed with a mean of 16 and a standard deviation of 0.3. What percent of the data is between 15.2 and 16?

So far I got: I wrote the limits in terms of the mean: 16 - 0.8 = 15.2 and 16 - 0 = 16.
Then I solved for t: t(0.3)= 0.8, t=2.67 which equals 99.3%.

This was a test question I got it wrong but I'm not sure where I went wrong because I tried to follow the book and I continue to get the same answer.

#### Subhotosh Khan

##### Super Moderator
Staff member
Re: Normally Distributed Data

Jen123 said:
Question: A set of data is normally distributed with a mean of 16 and a standard deviation of 0.3. What percent of the data is between 15.2 and 16?

So far I got: I wrote the limits in terms of the mean: 16 - 0.8 = 15.2 and 16 - 0 = 16.
Then I solved for t: t(0.3)= 0.8, t=2.67 which equals 99.3%.

This was a test question I got it wrong but I'm not sure where I went wrong because I tried to follow the book and I continue to get the same answer.
Look at z-distribution table:

$$\displaystyle z\, = \, \frac {x\, - \, \mu}{\sigma}$$

#### Jen123

##### New member
Re: Normally Distributed Data

I looked in my book for a z distribution table and i could not find it could you explain yourself a little more and identify your variables please I'm confused.
Thanks

#### stapel

##### Super Moderator
Staff member
Subhotosh Khan said:
Look at z-distribution table:

$$\displaystyle z\, = \, \frac {x\, - \, \mu}{\sigma}$$
Jen123 said:
I looked in my book for a z distribution table and i could not find it could you explain yourself a little more and identify your variables please
How on earth is your statistics course discussing "distributions" and "normality", if it hasn't yet covered the concepts of (and variables for) "mean" and "deviation", and has no information on z-tables...? :shock:

Eliz.

#### Jen123

##### New member
Re: Normally Distributed Data

I don't have a teacher, so I haven't discussed it with anyone. I just have a book and in the book it has nothing referring to a z table thats why I asked for further help. I still need the help of figuring out how to solve the problem the correct way, or could someone explain solving it with a z table.

#### stapel

##### Super Moderator
Staff member
Jen123 said:
I don't have a teacher.... I just have a book and in the book it has nothing referring to a z table.... could someone explain solving it with a z table.
Unfortunately, we are not able to teach courses within this environment. Since the various lessons you've found online (to supplement your apparently quite odd book) have not been sufficiently helpful, it may be time to consider taking a class, or hiring a tutor, in order to obtain the hours of instruction you have requested.

My best wishes to you in your studies!

Eliz.