Question

Need help,with exercise I’m learning math from exercise book so I’m prepared for ged next near been 20 years having issues with exercise like this have 10 just like it especially b can u help with a n b please show the steps my book says the formula is Z = X - u/o

Answer 1

From the given information, we know that the mean and standard deviare are, respectively,

`\begin{gathered} \mu=225 \\ \sigma=10 \end{gathered}`

Then, we need to use the z score value in order to answer part a and b.

Part a.

In this case, we need to find the z score values for 200 and 220 calories. For the first case, we have

`z=(X-\mu)/(\sigma)\Rightarrow z=(200-225)/(10)`

which gives

`z=-2.5`

For the second case, we have

`z=(X-\mu)/(\sigma)\Rightarrow z=(220-225)/(10)=-0.5`

So, we need to find the probability between z= -2.5 and z= -0.5 on the z-table. This is shown the the following picture:

Therefore, the answer for part a is: 0.30233

Part b.

In this case, we need to find the z score value for 190 calories and get the respective probability. Then, the z score is given by

`z=(190-225)/(10)=-3.5`

So, we need to find the following probability

`P(z<-3.5)`

which is equal to

`P(z<-3.5)=0.00023263`

as it is shown in the following picture:

Therefore, the answer for part b is: 0.00023263