Answer: 0.0475
Step-by-step explanation:
Given : A firm’s marketing manager believes that total sales X can be modeled using a normal distribution.
Where , Population mean : 
Standard deviation : 
To find : Probability that the firm’s sales will exceed $3 million i.e. $ 3,000,000.
∵ 
Then , for x= 3,000,000

Then , the probability that the firm’s sales will exceed $3 million is given by :-

Hence, the probability that the firm’s sales will exceed $3 million = 0.0475
The number of solutions of the equations can't be determined.
<h3>How to illustrate the information?</h3>
It should be noted an equation shows the relationship between the variables. It should be noted that the question is to find the number of solutions.
From the information, 3(5x + 2) = 15x
15x + 6 = 15x
Collect like terms
15x - 15x = - 6
0 = -6
Therefore, it can be see that the friend is incorrect as the number of solutions of the equations can't be determined.
Learn more about equations on:
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Answer: 9 boys remained in the choir.
Step-by-step explanation:
Let x be the number of of boys and y be the number of girls.
In a school choir, 1/2(half) of the members were girls.
i.e
(1)
At the end of the year, 3 boys left the choir, and the ratio of boys to girls became 3:4.
Put y= x from (1), we get

Thus , the number of boys : x= 12
Boys remained in the choir = 12-3=9
Answer:
y + 4 = 3(x + 5)
Step-by-step explanation:
The equation of a line in point- slope form is
y - b = m(x - a)
where m is the slope and (a, b) a point on the line
Here m = 3 and (a, b) = (- 5, - 4) , then
y - (- 4) = 3(x - (- 5) ) , that is
y + 4 = 3(x + 5)