Answer:
Option A: 3.59% is the correct answer
Step-by-step explanation:
Z-score is used to calculate the probabilities when mean and standard deviation is given.
Given
Mean = μ = 21
SD = σ = 5
We have to find the probability of selling 12 or less water heaters so our x value is 12
x = 12
The z-score of a value is calculated as:
z-score = (x-μ)/σ
Putting the values

Now z-score table will be used to calculate the probability for z= -1.8
So we will go for the row with -1.8 and column 0, which gives us: 0.03593
As we have to calculate the probability in percentage

Hence,
Option A: 3.59% is the correct answer
Answer: 90
Step-by-step explanation:
In the number 73,951, the digit 9 is on the third position, so you need to put the number of the position minus one zeros before it: ( position number 3, 3 - 1 = 2, so we put 2 zeros)
the 9 in that digit represents a 900.
now, 1/10 times that number is:
900*(1/10) = 900/10 = 90
then the answer is 90.
In the number 90, the value represented by the 9 is equal to 1./10 times the value represented by the 9 in 73,951
The value of c is 81/64 for the expression a perfect square trinomial.
<h3>
What is an Expression?</h3>
An expression can be defined as a mathematical statement that consists of variables, constants and mathematical operators simultaneously.
It is given that an expression
x² +9/4x +c is a perfect square polynomial
c =?
(a+b)² = a² +2ab+b²
2ab = 9/4
b = 9/8
c = b² = 81/64
Therefore the value of c is 81/64 for the expression a perfect square trinomial.
To know more about Expression
brainly.com/question/14083225
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Answer
Together, they have 99 marbles.
Explanation
Ravi has 33 marbles.
His brother has twice (two times) as many marbles as him. Ravi's brother has 33×2=66 marbles.
Together, they have 33+66=99 marbles.
The question is basically asking what 3.5 x 2.3 is. So the answer would be 8.05. If you read carefully it even tells you “times” I. The question. Hope this helps!!