Smartphones: A poll agency reports that 40% of teenagers aged 12-17 own smartphones. A random sample of 125 teenagers is drawn. Round your answers Espa to at least four decimal places as needed. Part 1 of 6 (a) Find the mean JA. The mean un is |0.40 X 5 Part 2 of 6 (b) Find the standard deviation on. The standard deviation On is |0.0438 X 5 Part 3 of 6 (c) Find the probability that more than 45% of the sampled teenagers own a smartphone. The probability that more than 45% of the sampled teenagers own a smartphone is |0.1271 X Part: 3 / 6 Part 4 of 6 (d) Find the probability that the proportion of the sampled teenagers who own a smartphone is between 0.35 and 0.45. The probability that the proportion of the sampled teenagers who own a smartphone is between 0.35 and 0.45 is