In China, four-year-olds average three hours a day unsupervised. Most of the unsupervised children live in rural areas, considered safe. Suppose that the standard deviation is 1.5 hours and the amount of time spent alone is normally distributed. We randomly select one Chinese four-year-old living in a rural area. We are interested in the amount of time the child spends alone per day. Seventy percent of the children spend at least how long per day unsupervised?  (Leave answer in decimal form rounded to 2 decimal places )  Answer:  hours

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