Answer:
14.63% probability that a student scores between 82 and 90
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

What is the probability that a student scores between 82 and 90?
This is the pvalue of Z when X = 90 subtracted by the pvalue of Z when X = 82. So
X = 90



has a pvalue of 0.9649
X = 82



has a pvalue of 0.8186
0.9649 - 0.8186 = 0.1463
14.63% probability that a student scores between 82 and 90
The function
represents a reflection of
across the y-axis ⇒ 3rd answer
Step-by-step explanation:
Let us revise the reflection across the axes
- If the function f(x) reflected across the x-axis, then its image is g(x) = - f(x)
- If the function f(x) reflected across the y-axis, then its image is g(x) = f(-x)
∵ 
∵ g(x) is the image of f(x) after reflection across the y-axis
- From the rule above reflection across the y-axis changes the sign of x
∴ 
∵ 
∵ 
∴ 
∴ 
The function
represents a reflection of
across the y-axis
Learn more:
You can learn more about reflection in brainly.com/question/5017530
#LearnwithBrainly
Answer:
Area of gray region = 
Step-by-step explanation:
The area covered by the furniture can be subtracted from the total area of the room to calculate the area of the gray region.
<em>Total</em> area of the room: 
Area taken up by furniture: 
Area of gray region = total area of the room - area taken up by furniture
Area of gray region = 
Remember to distribute the negative sign:
Area of gray region = 
Combine like terms:
Area of gray region = 
Answer:
30
Step-by-step explanation:
2/3 = x/18
2*18 = 3x
36 = 3x
x=12
so there are 12 boys
12+18=30
Answer:
look at the picture .................