Answer:
The standard error of the mean is 4.5.
Step-by-step explanation:
As we don't know the standard deviation of the population, we can estimate the standard error of the mean from the standard deviation of the sample as:

The sample is [30mins, 40 mins, 60 mins, 80 mins, 20 mins, 85 mins]. The size of the sample is n=6.
The mean of the sample is:

The standard deviation of the sample is calculated as:

Then, we can calculate the standard error of the mean as:

Answer: This is late but they can expect to pay b.)56.25%
Answer:
y = 50x+25
f(x) = 50x+25
Step-by-step explanation:
Using the slope intercept form of the equation, y = mx+b
where x is the amount per day and b is the flat fee
2 days
125 = 2x+b
5 days
275 = 5x+b
Subtract
275 = 4x+b
125 = 2x+b
---------------------
150 = 3x
Divide by 3
150/3 = 3x/3
50 =x
The cost per day is 50 dollars
y = 50x +b
Using the data for 2 days
125 = 50*2 +b
125 = 100 +b
125-100 = b
b = 25
The equation is y = 50x+25
f(x) = 50x+25
To graph, The x axis is number of days and the y axis is total cost
The number of days starts with 0, which is the y intercept
Let x = 0, y =25
Using the slope, we go 50 up and 1 to the right ( 50 dollars per day)
The next point plotted ins ( 1,50)
Draw a straight line
can you send me the actual problem so that i can solve it