Answer:
Mean = 30516.67
Standard deviation, s = 3996.55
P(x < 27000) = 0.0011518
Step-by-step explanation:
Given the data:
28500 35500 32600 36000 34000 25700 27500 29000 24600 31500 34500 26800
Mean, xbar = Σx / n = 366200 /12 = 30516.67
Standard deviation, s = [√Σ(x - xbar) / n-1]
Using calculator, s = 3996.55
The ZSCORE = (x - mean) / s/√n
Zscore = (27000 - 30516.67) / (3996.55/√12)
Zscore = - 3516.67 / 1153.7046
Zscore = - 3.048
P(x < 27000) = P(Z < - 3.049) = 0.0011518
Answer:
3
Step-by-step explanation:
Answer: option B is the correct answer.
Step-by-step explanation:
Susan drove at an average speed of 30 miles per hour for the first 30 miles of a trip.
Time = distance/speed
This means that time spent by Susan in travelling the first 30 miles would be
Time = 30/30 = 1 hour
He travelled at an average speed of 60 miles per hour for the remaining 30 miles of the trip.
Time = 30/60 = 0.5 hours
Total distance travelled is 30 + 30 = 60 miles.
Total time spent = 1 + 0.5 = 1.5 hours
Speed = distance/time
Average speed = 60/1.5 = 40 miles per hour.
