Step-by-step explanation:
We know that,
Where,
X = raw score = 84
μ = mean = 68
σ = standard deviation = 10
Putting the values,
The percent of his sales that were less than or equal to 84 inches, is
Therefore, the remaining 100-94.5=5.5% were more than 84 inches.
1/4 = 5/20
2/5 = 8/20
8/20 + 5/20 = 13/20 has been spent
Answer:
10 hours
Step-by-step explanation:
(150/x) + 1.5 + (450/(x+15)) = 600/x
Multiply through by x(x + 15):
150(x + 15) + 1.5x(x + 15) + 450x = 600(x + 15)
150x + 2250 + 1.5x^2 + 22.5x + 450x = 600x + 9000
150x + 2250 + 1.5x^2 + 22.5x + 450x - 600x - 9000 = 0
1.5x^2 + 22.5x - 6750 = 0
x = (-22.5 +/- sqrt(22.5^2 - 4(1.5)(-6750))) / (2*1.5)
x = (-22.5 +/- sqrt(506.25 + 40500)) / 3
x = (-22.5 +/- sqrt(41006.25)) / 3
x = (-22.5 +/- 202.5) / 3
x = 180/3 or -225/3
x = 60 or -75
But a negative number doesn't make sense, so therefore x = 60, so the journey took 600/60 = 10 hours.
Answer:
see explanation
Step-by-step explanation:
These are the terms of an arithmetic sequence with n th term
= a + (n - 1)d
where a is the first term and d the common difference
d = 25 - 20 = 30 - 25 = 5 and a = 20, hence
= 20 + 5(n - 1) = 20 + 5n - 5 = 5n + 15 ← n th term formula
