Answer:
Project 4 Score ; 41
Step-by-step explanation:
Assuming that Project 4's score is x;
( Project 1 + Project 2 + Project 3 + Project 4 ) / 4 ⇒ take to substituting the value of each Project, provided Project 4's score being x;
45 = 42 + 49 + 48 + x / 4 ⇒ combine like terms,
45 = ( 139 + x ) / 4 ⇒ let 4 be a common denominator among numerator terms,
45 = 139 / 4 + x / 4 ⇒ divide 139 over 4,
45 = 34.75 + x / 4 ⇒ subtract 34.75 from either side,
10.25 = x / 4 ⇒ Multiply either side by 4,
x = 41 = Score of Project 4,
Solution; Project 4 ⇒ 41