675 people will have score between 85 and 120
Step-by-step explanation:
Given
Mean = 100
SD = 15
If we have to find percentage of score between two values we have to find the z-score for both values and then area under the curve for both values
z-score is given by:
for a value x:

So,
For 85:


Now we have to find the area under the curve for both values of z-score. z-score tables are used for this purpose.
So,
For z1 : 0.1587
For z2: 0.9082
The area between z11 and z2:

So the probability of score between 85 and 120 is 0.7495
As the sample is of 900 people, the people with scores between 85 and 120 will be:
900*0.7495 = 674.55 people
Rounding off to nearest whole number
675 people will have score between 85 and 120
Keywords: Probability, SD
Learn more about probability at:
#LearnwithBrainly
YES if you simplify 15:10 by 5 since they can both be divided by 5 the ratio becomes 3:2
Answer:

y = (x + 1) (x - 1) (x - 3)
Use the distributive property to multiply x+1 by x-1 and combine like terms.
y = (x² - 1) (x - 3)
Use the distributive property to multiply x² - 1 by x - 3.
<u>y = x³ - 3x² - x + 3.</u>
ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ

Answer: (1, 5)
Explanation:
y > 2x
y > 3
y = 5
x = 1
5 > 2(1)
5 > 2 yes
5 > 3 yes