to run a symmetry test on a polar, we can simply do a few ( r , θ ) replacements, if the equation resulting from the replacements, resembles the original, then it has that symmetry type, now, let's recall the symmetry trigonometry identity, cos(-θ) = cos(θ).
The value of 27, because it’s greater than 26.7 and less than 29.3.
You should find the confidence Interval at 95%
The formula to apply is;
where C.I is the confidence interval, x is the mean of the sample, z is the z* value from the standard normal distribution for 95% confidence interval, δ is the standard deviation and n is the sample size
Substitute values in the formula
Upper limit is = 28+1.2652=29.2625
Lower limit is =28-1.2652=26.7348
The value 27 is within 95% confidence interval because it is greater than 26.7 and less than 29.3