The z-score of the sale of mobile phones on that day is 1.75
Step-by-step explanation:
The formula of z-score is z = (x - μ)/σ, where:
- x is the score
- μ is the mean
- σ is the standard deviation
∵ The mean sale was 45
∴ μ = 45
∵ The standard deviation was 4
∴ σ = 4
∵ 52 mobile phones were sold on a particular day
∴ x = 52
To find z-score of the sale of mobile phones on that day substitute the values of x, μ, and σ in the formula of z-score
∵ 
∴ 
∴ z = 1.75
The z-score of the sale of mobile phones on that day is 1.75
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Answer: Length = 15, Width = 12
Step-by-step explanation:
L = length
W = width
L = W+ 3
perimeter = 2L + 2W
54 = 2(W+3) + 2W
54 = 2W + 6 + 2W
54 = 4W + 6
54 - 6 = 4W
48 = 4W
W = 
W = 12
now to find the length, plug the width into the equation L = W + 3
length:
L = W+3
L=12 +3
L = 15
Answer:
1/3
Step-by-step explanation:
SOLUTION
Write out the equation

To solve this system of equation, the aprropriate method will be substitution
Substitute the expression for y into the second equation for y, we have

Expand the paranthesis we have

Divide both sides by 4, we have

Since the value of x has been obtained, we substitute into the first equation

Therefore
x = -3, y= -4