Answer: Mean = 52.8 mins
Step-by-step explanation:
We have lapses of 30 minutes, so we can write the average for each, this means that:
0 < t < 30 can be averaged to the middle of the range: 15 min.
Doing this, we have that:
7 students 15 min
27 students 45 min
12 students 75 min
4 students 105 min.
Now we can calculate the mean:
mean = (x1*n1 + x2*n2 + ...)/N
where x1 is the amount of time 1, and n1 is the number of students associated to that time and so on. N is the total number of students
Mean = (7*15min + 27*45min + 12*75min + 4*105min)/(7 + 27 + 12 + 4)
Mean = 52.8 mins
The answert to the a portion is A: 2,3,5,8
Answer:
2.75x + 114 = 320.25
x = $75
Step-by-step explanation:
2.75x + 114 = 320.25
number of hours of labor (2.75) times the cost per hour of labor (x) + cost of parts (114) = total cost (320.25)
2.75x + 114 = 320.25
subtract 114 from both sides
2.75x = 206.25
divide both sides by 2.75
x = 75
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check the math:
2.75(75) = 114 = 206.25 + 114 = 320.25