A set of data items is normally distributed with a mean of 200 and a standard deviation of 30. Find the data item in this distribution that corresponds to the following z-score: z = -2.8

Question

kropot72 · Answer

Use the formula
$$z=\frac{X-\mu}{\sigma}$$
Substituting the given values we get
$$-2.8=\frac{X-200}{30}\ .....(1)$$
Now you just need to solve equation (1) to find the value of X, the required data item.

anonymous · Answer

My brain is tried of trying to solve it can you solve for me.

kropot72 · Answer

To solve the equation:
1. Multiply both sides of equation (1) by 30.
2. After completing step 1, add 200 to both sides of the resulting equation.