Hi All!

We have this exercise in class where we are given the table below:

---------------Estimate of the------Estimate of the
-----------------mean sales*-------Std. Deviation
Agent 1------------230-----------------60
Agent 2------------280-----------------50
Agent 3------------220-----------------60

* - for the following year

From the combined estimates of the mean and standard deviation of sales of the product, calculate the probability that sales of the product for the next year will be above 300 units.

I computed by averaging the mean sales and std. deviation and computed for z=(300-243.33)/56.67=1.0 from the table (Areas under the normal curve) I got the value of 0.84134

Is my interpretation of the problem correct? On the calculation of z, should I use 301 instead of 300, since the problem stated above 300 units?

Please help.