Step-by-step explanation:
Draw picture of 2 points (-1, 7), (1, 5) at line x and y
and use the formula
slope = (y2 - y1)/(x2 - x1)
If convexity to the right slope +
If convexity to the left slope -
Answer:
a
The distribution of X is normal
b

c

Step-by-step explanation:
From the question we are told that
The population mean is 
The standard deviation is 
Generally given from the question that the amount of time spent alone by the population size is normally distributed then then the distribution of X (i.e the amount of time spent by the sample size (the one Mercurian)) will be normally distributed
Generally the probability that the child spend less than one hour in a day is mathematically represented as

Here 
So


From the z-table the value of

So 
Generally the percentage of children that spends over 3.5 hours unsupervised is mathematically represented as



From the z-table the value of

So 
Answer:
Input complete question please.
Answer:
282.7 cm²
Step-by-step explanation:
Hello There!
To find the area of the shaded area we are going to want to find the area of the whole semi circle and subtract it by the area of the smaller semi circle
To find the area of a semicircle we use this formula

where r = radius
For the large semi circle
The radius of the larger semi circle is 18 cm so we plug in 18 into r in the formula
So..

So the area of the whole semi circle is 508.9380099 cm²
Now to find the area of the smaller semi circle
The radius for the smaller semi circle is 12 cm so we plug in 12 into r in the formula

so the area of the smaller semi circle is 226.1946711cm²
Finally we want to subtract the area of the smaller semi circle from the area of the whole semi circle
508.9380099 - 226.1946711 = 282.7433388
Finally we want to round to the nearest tenth and we get that the area of the rainbow is 282.7 cm²