Answer:
Sample mean from population A has probably more accurate estimate of its population mean than the sample mean from population B.
Step-by-step explanation:
To yield a more accurate estimate of the population mean, margin of error should be minimized.
margin of error (ME) of the mean can be calculated using the formula
ME=
where
- z is the corresponding statistic in the given confidence level(z-score or t-score)
- s is the standard deviation of the sample (or of the population if it is known)
for a given confidence level, and the same standard deviation, as the sample size increases, margin of error decreases.
Thus, random sample of 50 people from population A, has smaller margin of error than the sample of 20 people from population B.
Therefore, sample mean from population A has probably more accurate estimate of its population mean than the sample mean from population B.
Roberto paints 1/6 of a room in 1 hour.
Julio paints1/8 of a room in 1 hour.
Working together, they paint (1/6 + 1/8) = (4/24 + 3/24) = 7/24 room per hour.
The reciprocal unit rate is 24/7 hour per room = <em>3-3/7 hours</em> per room.
Lets get an example, for this example lets use 24/30 x 30/60
Without dividing out GCFs you would get 24x12 over 30 x 60 which is 288/1800
With dividing out GCFs you get 2/1 x 5/1 Which is 7 :)
What hell there is nothings ??