9514 1404 393
Answer:
y-4 = -2(x+1)
Step-by-step explanation:
The point-slope equation of a line is ...
y -k = m(x -h) . . . . . line with slope m through point (h, k)
You have m = -2 and (h, k) = (-1, 4). Putting these numbers into the above form gives ...
y -4 = -2(x +1)
First, make up some variables to represent the number of Girls and Boys in the choir.
B = number of boys
G = number of girls
You know that there are 4 times as many girls in the choir as boys. Therefore, the equation you can write is:

If you cross-multiply, then you get the simplified equation:
G = 4B
Intuitively this makes sense since if you multiplied the number of boys in the class by 4, that would be equal to the number of girls you have.
Now, we know that the total class size is 60. So girls plus boys equals 60:
G+B = 60
To solve the equation, replace the G in this equation with the replacement you found before, 4B.
G + B = 60 -->
4B + B = 60 -->
5B = 60 -->
B = 12
However, you are trying to find the number of girls, so plug the answer back into your equation.
G + B = 60 -->
G + 12 = 60 -->
G + 12 -12 = 60 - 12 -->
G = 48
The number of girls you have is 48.
1800 divided by 25 is 72. He types 72 words per minute.
This question is incomplete, the complete question is;
In a survey, 55% of the voters support a particular referendum. If 40 voters are chosen at random,
find the mean and variance for the number of voters who support the referendum.
Answer:
a) The Mean is 22
b) Variance is 9.9
Step-by-step explanation:
Given that;
55% of the voters support a particular referendum p = 0.55
q = 1 - p = 1 - 0.55 = 0.45
sample size n = 40
a)
Mean = sample size n × p
Mean = 40 × 0.55
Mean = 22
Therefore the Mean is 22
b)
Variance = n × p × q
so we substitute
Variance = 40 × 0.55 × 0.45
Variance = 9.9
Therefore the Variance is 9.9