I believe the problem ask for s which is the standard
deviation. We must recall that the formula for z statistic is stated as:
z = (x – x over bar) / s
Where,
z = z statistic = 2.5
x = sample value or sample score = 102
x over bar = the sample mean or sample average = 100
s = standard deviation = unknown
Rewriting the equation in terms of s:
s = (x – x over bar) / z
Substituting the given values into the equation:
s = (102 – 100) / 2.5
s = 0.8
Therefore the standard deviation s is 0.8
U² - 16 u + 64 = ( u - 8 )²
because: A² - 2 A B + B² = ( A - B )²
Answer: 64
50 X (40 X$20) = 50 X $800 = $40,000
15 X (4 X (50% X $20+ $50)) = 15 X (4 X $60) = 15 X 240 = $3600
$40,000 + $3600 = $43,600 Total payroll
$3,600/$43,600 = .0825688073 as a percent rounded to the nearest tenth is 8.3%
1.15/3 = 20 minutes worth = 0.383
60 minutes+20 minutes=80 minutes = 1.15+0.383=1.53
1.5/3 = 0.5 = 20 minutes
60 minutes+20 minutes=80 minutes =1.5+0.5=2
2-1.53=0.47 therefore it is 0.47 minutes quicker with Model A
