S<span>tep-1 : Multiply the coefficient of the first term by the constant </span><span> <span> 3</span> • 4 = 12</span>
<span>Step-2 : Find two factors of </span> 12 <span> whose sum equals the coefficient of the middle term, which is </span><span> 13 </span><span>. </span><span><span>
Answer is From all those aforementioned, the true statement is: Thanh’s grade is 2.5 standard deviations below the mean of the test grades.
explanation
The z scores are standard deviations. If, for example, a tool returns a z score of +2.5, it means that the result is a standard deviation of 2.5. Very high or very low (negative) z scores associated
with very low p values are at the ends of the normal distribution.
