(Solved): The lower bound of the confidence interval is calculated using the expression \( \bar{x}-2, \frac{d ...
The lower bound of the confidence interval is calculated using the expression \( \bar{x}-2, \frac{d}{\sqrt{n}} \). 5 ubstitute the values \( \bar{x}=37, z \) an \( =1.645, d=5 \), and \( n=60 \) into this formula and simplify, founding the final value to two decimal places. \[ x-7 \times \frac{\pi}{\sqrt{n}}=37-\left(\frac{5}{\sqrt{60}}\right) \] The upper bound is found in a simiar fashion, but now we will add the margin of error instead of subtracting a. Again, round the final value to two decimai piaces. \[ x+2+2 \frac{a}{\sqrt{n}}=37+\left(\frac{5}{\sqrt{60}}\right) \] Thus, a \( 90 \% \) confidence interval for the poputation mean in a sample of 60 items with a sample mean of 37 and a population standard deviation of 5 is