Smart phone: Among 240 cell phone owners aged 18-24 surveyed, 108 said their phone was an Android phone. Part 1 of 3 (a) Find a point estimate for the proportion of cell phone owners aged 18-24 who have an Android phone. Round the answer to at least three decimal places. The point estimate for the proportion of cell phone owners aged 18-24 who have an Android phone is 0.450 X G Part: 1/3 Part 2 of 3 (b) Construct a 90% confidence interval for the proportion of cell phone owners aged 18-24 who have an Android phone. Round the answers to at least three decimal places. A 90% confidence interval for the proportion of cell phone owners aged 18-24 who have an Android phone is