A set of data has a normal distribution with a mean of 5.1 and a standard deviation of 0.9. Find the percent of data between 4.2 and 5.1.
Answer: The correct option is B) about 34%
Proof:
We have to find 
To find , we need to use z score formula:
When x = 4.2, we have:
When x = 5.1, we have:
Therefore, we have to find 
Using the standard normal table, we have:
= 
or 34.13%
= 34% approximately
Therefore, the percent of data between 4.2 and 5.1 is about 34%
The area of a right angled triangle with sides of length 9cm, 12cm and 15cm in square centimeters is 54 sq cm.
The formula to calculate the area of a right triangle is given by:
Area of Right Triangle, A = (½) × b × h square units
Where, “b” is the base (adjacent side) and “h” is the height (perpendicular side). Hence, the area of the right triangle is the product of base and height and then divide the product by 2.
We know that the hypotenuse is the longest side. So, the area of a right angled triangle will be half of the product of the remaining two sides.
Given sides of the triangle:
a=9cm
b=12cm
c=15cm
From this we know that the hypotenuse is c. Are of the triangle will be obtained by the other two sides.
∴Area = 
x 9 x 12
= 54
1700 because I multiply 30 x 20 then 20 x 5 then 30 x 5 then add them all up and multiply your answer by 2
Answer:
-3/15 is the difference between 6/15-9/15
