Answer:
12.5 un^2
Step-by-step explanation:
The formula for area of a trapezoid is (a+b)/2 *h
a and b are the shorter and longer bases respectively. H is height, you have both.
Simply plug it into the equation and find your answer.
(2.5+7.5)/2 *2.5 = 5*2.5 which is equal to 12.5. Add units.
Step-by-step explanation:
13.6 is the answer because 1cm is 10 cm
The sample size should be 250.
Our margin of error is 4%, or 0.04. We use the formula

To find the z-score:
Convert 98% to a decimal: 0.98
Subtract from 1: 1-0.98 = 0.02
Divide both sides by 2: 0.02/2 = 0.01
Subtract from 1: 1-0.01 = 0.99
Using a z-table (http://www.z-table.com) we see that this value has a z-score of approximately 2.33. Using this, our margin of error and our proportion, we have:

Divide both sides by 2.33:

Square both sides:

Multiply both sides by n:

Divide both sides to isolate n:
Answer:
45
Step-by-step explanation:
Let the unit place be ‘x'
Tenth place be y
The number is 10y+x
x+y = 9 (according to the condition) (1)
Digits are interchanged Unit place' y ‘& tenth place ‘ x'
New no is 10x +y
This is 9 more than the original number
10x+ y = 10y+x +9
10x-x+y-10y = 9
9x-9y= 9
x-y = 1 (dividing by 9) (2)
Adding the two equations
2x = 10
x= 5
Substituting the value of x in first equation
y = 4
The number is 45, the original number is 54 this is 9 more of the new number.
Each day of earning $140 on the day, the tenth day you will earn 1,400
$140x10