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: x=6, y=20
Step-by-step explanation:
Since ΔBCD and ΔTUS are congruent triangles, we can set the sides equal to each other.
y=2y-20 [subtract both sides by 2y]
-y=-20 [divide both sides by -1]
y=20
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3x+32=9x-4 [add both sides by 4, and subtract both sides by 3x]
36=6x [divide both sides by 6]
x=6
Answer:
30 more bags
Step-by-step explanation:
The correct answer is 15:25