Smartphones: A poll agency reports that 86% of teenagers aged 12-17 own smartphones. A random sample of 270 teenagers is drawn. Round your answers to at least four decimal places as needed. (a) Find the mean p3. memeanpsis E]- E (b) Find the standard deviation 53' The standard deviation 63 is E]. (c) Find the probability that more than 90% of the sampled teenagers own a smartphone. The probability that more than 90% of the sampled teenagers own a smartphone is [j . (d) Find the probability that the proportion of the sampled teenagers who own a smartphone is between 0.83 and 0.90. The probability that the proportion of the sampled teenagers who own a smartphone is between 0.83 and 0.90 is D. (e) Find the probability that less than 90% of sampled teenagers own sma rtphones. The probability that less than 90% of sampled teenagers own smartphones is D . (f) Would it be unusual if less than 80% of the sampled teenagers owned smartphones? [t (Choose one) V be unusual if less than 80% of the sampled teenagers owned smartphones, since the probability is g. [:l