Answer:
x = 125
Step-by-step explanation:
4 hrs : 200 mi
2.5 hrs : x mi
4/2.5 = 1.6 hrs
200/1.6 = 125 mi
x = 125 mi
 
        
             
        
        
        
Answer:
A normal distribution or z-test is used to construct a confidence interval.
Step-by-step explanation:
We are given the following in the question:
Sample mean,  = $3120
 = $3120
Sample size, n = 40
Population standard deviation, σ = $677
The distribution of earnings of college is a normal distribution.
Conditions:
- Since we are given the population standard deviation and the the sample size is also greater than 30.
Conclusion:
Thus, we use a normal distribution or z-test to construct a confidence interval.
 
        
             
        
        
        
Answer: 
x = 54°
y = 66° 
Step-by-step explanation:
x + y = 120° (given)
x = y - 12
Then, y + y - 12 = 120°
(y + y) - 12 = 120°
2y - 12 = 120°
2y = 120 + 12 = 132°
y = 132/2 = 66°
x = y - 12 = 66 - 12 = 54°
There you go :)
 
        
             
        
        
        
Answer:
A. t(x) = 450 - 0.06x
Step-by-step explanation:
The layer which is originally 450 m thick is decreasing by 0.06 m.
450 - 0.06
... per day. x represents days.
0.06x
So, 
450 - 0.06x