Plug in your coefficients
$62 is both numbers added together
find the square root and of 1+i√3
1) 3.8x + 5.2x - 6.7 = 11.3
9x = 11.3 + 6.7
9x = 18
x = 18/9
x = 2
2) 7.8y - 4.9 - 5.4y = 2.3
2.4y = 7.2
y = 7.2/2.4
y = 3
3)



Multiply by 3 by both sides:

Simplify:
2x = 18
x = 18/2
x = 9
4)

Do lowest common denominator:



Simplify by 5 by both sides:


Z = (x - mu)/sigma
z = (6.19 - 3.77)/3.39
z = 0.71386430678467
z = 0.71
The approximate z score, rounded to two decimal places, is 0.71