Answer: Point of estimation = 32.60
Margin of error = 1.175.
95% confidence interval would be (81.95,84.45).
Step-by-step explanation:
Since we have given that
n = 49
Average = $32.60
Standard deviation = $5
We need to find:
1) Point of estimation for the mean of the population:
[tex]\mu=\$32.60[/tex]
2) At 90% level of confidence, z = 1.645
Margin of error would be
[tex]z\dfrac{\sigma}{\sqrt{n}}\\\\=1.645\times \dfrac{5}{\sqrt{49}}\\\\=1.645\times \dfrac{5}{7}\\\\=1.175[/tex]
So, Margin of error = 1.175.
3) At 90% level of confidence, interval would be
[tex]\bar{x}\pm 1.175\\\\=32.60\pm 1.175\\\\=(32.60-1.175,32.60+1.175)\\\\=(31.425,33.775)\\\\=(31.43,33.76)[/tex]
Hence, 90% confidence interval would be (31.43,33.76).