y≤-2x +2
y< 1/3x +2
this is the answer to this
Answer:
The mechanic who worked 5 hours charged $115 per hour, the one who worked 15 hours charged $120 per hour.
Step-by-step explanation:
x = rate of mechanic who worked 5 hours
y = rate of mechanic who worked 15 hours
Then
x + y = 235
5x + 15y = 2375
Just solve these 2 equations above for x and y.
x + y = 235 ⇒ x = 235 - y
Substitute into second equation to find y.
5(235 - y) + 15y = 2375
1175 - 5y + 15y = 2375
10y = 1200
y = 1200/10 = 120
x = 235 - y = 235 - 120 = 115
Given:
Sample size, n = 40
Sample mean, xb = $6.88
Population std. deviation, σ = $1.92 (known)
Confidence interval = 90%
Assume normal distribution for the population.
The confidence interval is
(xb + 1.645*(σ/√n), xb - 1.645*(σ/√n)
= (6.88 + (1.645*1.92)/√40, 6.88 - (1.645*1.92)/√40)
= (7.38, 6.38)
Answer: The 90% confidence interval is (7.38, 6.38)
Answer:
29 7/52
Step-by-step explanation:
