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.
Option C:
The rate of change is $3 per picture.
Solution:
<em>Rate of change is same as the slope of the line.</em>
Take any two points on the graph.
(0, 20) and (20, 80) are two points on the line of the graph.
Slope of two points formula:
m = 3
The rate of change is $3 per picture.
Hence option C is the correct answer.
5388.33$ was last years salary increase