ANSWER:
0.83
STEP-BY-STEP EXPLANATION:
We have that the formula corresponding to the problem is the following:
[tex]P(\bar{x}We replace the corresponding values and we are left with the following:[tex]\begin{gathered} P(\bar{x}\ge28)=P(Z\ge\frac{28-30}{21}\cdot\sqrt[]{100}) \\ P(\bar{x}\ge28)=P(Z\ge-0.9524) \\ P(\bar{x}\ge28)=P(Z<0.9524) \end{gathered}[/tex]For this value of Z, the probability is 0.83
