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
So, dimensional analysis will help with this
Hope this helps!
The experimental probability of tossing tails is 3/10
9x - y = 5
7x - 6y = 5
Solve both equations for one variable. I'll solve for y.
9x - y = 5 Subtract 9x from both sides
-y = -9x + 5 Divide both sides by -1
y = 9x - 5
7x - 6y = 5 Subtract 7x from both sides
-6y = -7x + 5 Divide both sides by -6
y =
x -
Since both equations equal y, you can set them equal to each other and solve for x.
9x - 5 =<span>
x -
Multiply both sides by 6 to eliminate the fractions
54x - 30 = 7x - 5 Subtract 7x from both sides
47x - 30 = -5 Add 30 to both sides
47x = 25 Divide both sides by 47
x = </span>
Now, plug that x-value into the x of either equation. I'll plug it into 9x - y = 5.
9x - y = 5 Plug in the x-value
9(<span>
) - y = 5 Multiply
</span>
- y = 5 Subtract <span>
from both sides
</span>-y = <span>0.21276595744 (I had to convert it to a decimal) Divide both sides by -1
y = -</span><span>0.21276595744
So, the answer to the system is (</span>0.53191489361, -<span>0.21276595744)</span>
