Please HIGHLIGHT the answers; detailed answers are not required.

PART A

Select Options: (equal to/at most/at least)

A social network provides a variety of statistics on its website that detail the growth and popularity of the site. On average, 27 percent of 18 to 34-year-olds check their social network profiles before getting out of bed in the morning. Suppose this percentage follows a normal distribution with a standard deviation of five percent. (a) Find the probability that the percent of 18 to 34-year-olds who check the social network before getting out of bed in the morning is at least 31. (Round your answer to four decimal places.) (b) Find the 95th percentile, and express it in a sentence. (Round your answer to two decimal places.) 95% of 18 to 34-year-olds who check the social network before getting out of bed in the morning is -Select-+- v .Describe a normal probability distribution. (Select all that apply.) O models discrete random variables O bell-shaped symmetric around the mean O mean, median, and mode all equivalent O uniform-shaped O skewed to the right O bimodal O most of the data fall within 3 standard deviations from the meanFind z such that 18% of the area under the standard normal curve lies to the right of z. (Round your answer to two decimal places.) LA USE SALTFind 2 such that I54fu of the standard normal curve lies between 2 and 2. [Round your answer to two decimal places.) I use SALT : Many people consider their smart phone to be essential! Communication, news, Internet, entertainment, photos, and just keeping current are all conveniently possible with a smart phone. However, the battery better be charged or the phone is useless. Battery life of course depends on the frequency, duration, and type of use. One study involving heavy use of the phones showed the mean of the battery life to be 10.75 hours with a standard deviation of 2.5 hours. Then the battery needs to be recharged. Assume the battery life between charges is normally distributed. LA USE SALT (a) Find the probability that with heavy use, the battery life exceeds 11 hours. (Round your answer to four decimal places.) (b) You are planning your recharging schedule so that the probability your phone will die is no more than 5%. After how many hours should you plan to recharge your phone? (Round your answer to the nearest tenth of an hour.) hoursExpress Courier Service has found that the delivery time for packages is normally distributed, with mean 14 hours and standard deviation 3 hours. LA USE SALT (a) For a package selected at random, what is the probability that it will be delivered in 18 hours or less? (Round your answer to four decimal places.) (b) What should be the guaranteed delivery time on all packages in order to be 95% sure that the package will be delivered before this time? (Hint: Note that 5% of the packages will be delivered at a time beyond the guaranteed time period.) (Round your answer to one decimal place.) hr