It is a because the model is up then b so it will be a
Z = (X-Mean)/SD
<span>z1 = (580-600)/20 = - 1 </span>
<span>z2 = (620-600)/20 = + 1 </span>
<span>According to the Empirical Rule 68-95-99.7 </span>
<span>Mean +/- 1*SD covers 68% of the values </span>
<span>Therefore, required percent is 68%
hopes this help :) :D :)</span>
Sorry I have to go to baseball bye
Linear is the correct answer
23^2 - 17^2
= (23-17)(23+17)
= 6 * 40
= 240