Answer:
1. x = -15
2. x = 0.25 or x = 1/4
Step-by-step explanation:
1.
8 + 9.8x + 9 = 3.8x - 16 + 3.8x
Simplify both sides
17 + 9.8x = 7.6x - 16
-17 -17
9.8x = 7.6x - 33
-7.6x -7.6x
2.2x = -33
Divide by 2.2
x = -15
2.
-2x - 10 = -14x - 7
+7 +7
-2x - 3 = -14x
+2x +2x
-3 = -12x
Divide by -12
0.25 = x
x = 0.25 or x = 1/4
10. When events are independent, the joint probability is the product of the individual probabilities.
... p(senior & female) = p(senior) × p(female) = 0.30 × 0.54 = 0.162 = 16.2%
11. When events are mutually exclusive, the probability of one or another is the sum of the individual probabilities.
... p(soph or frosh) = p(soph) + p(frosh) = 0.28 + 0.26 = 0.54 = 54%
