Answer: 99% confidence interval would be [tex](1346.37,1553.63)[/tex]
Step-by-step explanation:
Since we have given that
Sample size = 30
Sample mean = $1450
Standard deviation = $220
We need to find the 99% confidence interval.
So, z = 2.58
So, confidence interval would be
[tex]\bar{x}\pm z\dfrac{\sigma}{\sqrt{n}}\\\\=1450\pm 2.58\times \dfrac{220}{\sqrt{30}}\\\\=1450\pm 103.63\\\\=(1450-103.63,1450+103.63)\\\\=(1346.37,1553.63)[/tex]
Hence, 99% confidence interval would be [tex](1346.37,1553.63)[/tex]