Given:
Area of a circle, A=50.265 sq. units.
Radius of circle, r = 4 units.
To find:
The value of π to the nearest thousandth.
Solution:
Formula for area of a circle is
Now, using expression, we can find the value of π.
Approximate the value to the nearest thousandth (three digits after decimal).
Therefore, the approximated value of π is 3.142.
Answer: 95% confidence interval for the difference between the proportions would be (1.31, 1.39).
Step-by-step explanation:
Since we have given that
Number of alluvial wells = 349
Number of quaternary wells = 143
Number of alluvial wells that had concentrations above 0.1 = 182
Number of quaternary wells that had concentrations above 0.1 = 112
Average of alluvial wells = 0.27
Standard deviation = 0.4
Average of quaternary wells = 1.62
Standard deviation =1.70
So, 95% confidence interval gives
alpha = 5% level of significance.
So, 95% confidence interval becomes,
Hence, 95% confidence interval for the difference between the proportions would be (1.31, 1.39).