Answer:
d
Step-by-step explanation:
Answer: 2.5%
Step-by-step explanation:
Mean score = 65
Standard deviation = 5
Score (x) = >75
Z-score = [(score - mean) ÷ standard deviation]
Z - score = [(75 - 65) ÷ 5]
Z - score = 10 ÷ 5 = 2
P(score higher than 75) = 100 - 95 = 5/2 = 2.5%
Answer:
x = 5/(10 - a - b)
Step-by-step explanation:
Solve for x:
4 + 3 x - a x = 9 - 7 x + b x
Collect in terms of x:
x (3 - a) + 4 = 9 - 7 x + b x
Collect in terms of x:
x (3 - a) + 4 = x (b - 7) + 9
Subtract (b - 7) x + 4 from both sides:
x (10 - a - b) = 5
Divide both sides by 10 - a - b:
Answer: x = 5/(10 - a - b)
Answer: 3
Step-by-step explanation:
Let E be the event of that student pierces ear and N be the event of that student pierces nose.
Given: 

For any two event A and B, we have

Similarly , 

Hence, 3 students have piercings both on their ears and their noses.
Answer:
* is 
Step-by-step explanation:
(7x + 3)(x + 3)
=
+ 24x + 9