The Circumference of the circle is 
15.7
 and Area is 
19.625
        
             
        
        
        
Answer:
 
 
b. 14.573 and 43.195.
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population mean or variance lies between an upper and lower interval".  
The margin of error is the range of values below and above the sample statistic in a confidence interval.
The Chi square distribution is the distribution of the sum of squared standard normal deviates .
2) Solution to the problem
The confidence interval for the population variance is given by the following formula:
 
We need on this case to calculate the critical values. First we need to calculate the degrees of freedom given by:
 
Since the Confidence is 0.95 or 95%, the value of  and
 and  , and we can use excel, a calculator or a table for the Chis square distribution with 27 degrees of freedom to find the critical values. We need a value that accumulates 0.025 of the area on the left tail and 0.025 of the area on the right tail.
, and we can use excel, a calculator or a table for the Chis square distribution with 27 degrees of freedom to find the critical values. We need a value that accumulates 0.025 of the area on the left tail and 0.025 of the area on the right tail.  
The excel commands would be: "=CHISQ.INV(0.025,27)" "=CHISQ.INV(0.975,27)". so for this case the critical values are:
 
 
b. 14.573 and 43.195.
 
        
             
        
        
        
Answer:
B ≥ 209
Step-by-step explanation:
This is the equation - 25b + 525 ≥ 5750  .      
Comment if I solved it incorrectly ;-;   
 
        
             
        
        
        
Answer:
$2.30
Step-by-step explanation:
The original price is $2.30 an it goes up by 100% which means another 2.30. So add 2.30 and 2.30 together you get 4.60 now divide that by two since the magazine is 50% off and you get the original price which was 2.30