Answer:
solved
Step-by-step explanation:
Mean = 12
SD = 2
Answer to part 2) Less than 7 months
P(x < 7)
P(x < 7) = P(z < (7-12)/2) = P(z < -2.5)
This probability can be obtained by referring to the Z table
Thus P(x < 7) = 0.0062
1) Between 7 and 12 months
P(7 < x < 12) = P( x< 12) - P(x < 7)
We have P(x < 12) = 0 ......[because mean = 12]
and P(x < 7) = 0.0062 ...[this we got is part a]
Thus on plugging these values we get
P( 7 < x < 12) = 0.5 - 0.0062 = 0.4938
Thus P(7 < x < 12) = 0.4938
3
Take the square root of both sides to solve and you get a= 0.4,-0.4
Answer:
371
Step-by-step explanation:
y=x^2-2x-15 (1) y=8x-40 (2)
8x-40=x^2-2x-15
X^2+10x-25=0
(x-5)^2
×=5 y=0
Answer: D. 0.9967
Step-by-step explanation: To solve this, you need to do the z-score formula with both numbers. So 30-22/2.5 = 3.2. On the z-score chart, that equals .9993. Hold onto that number. Then you do the same with 15. 15-22/2.5 = -2.8. On the z score chart, that equals .0026. Subtract those numbers. .9993 - .0026 = .9967. It's not as compacted as it looks <3