Answer:
74 mph
Step-by-step explanation:
step 1
Find the total time
A sailboat started his journey at 6:30 am and reached his destination at 11:45 pm
so
from 6:30 am to 12:00 pm ----> there are 5 hours + 30 minutes=5.5 hours
from 12:00 pm to 11:45 pm ----> there are 11 hours + 45 minutes=11.75 hours
The total time is
5.5+11.75=17.25 hours
step 2
Find the average speed
we know that
The average speed is equal to divide the total distance by the total time
Answer: The margin of error = 3.71, confidence interval = (354.04, 361.46) and it means that mean cost is lies within the confidence interval.
Step-by-step explanation:
Since we have given that
Sample size = 400
Mean = $357.75
Standard deviation = $37.89
At 95% confidence level, z = 1.96
We first find the margin of error.
Margin of error is given by
95% confidence interval would be
Hence, the margin of error = 3.71, confidence interval = (354.04, 361.46) and it means that mean cost is lies within the confidence interval.