The sleeping time at night of the people is normally distributed. Based on a random sample of 10 people, the 95% confidence interval for the true mean of sleeping time was obtained as 6.5

Extracted text: The sleeping time at night of the people is normally distributed. Based on a random sample of 10 people, the 95% confidence interval for the true mean of sleeping time was obtained as 6.5< u=""><7.7 hours.="" a)="" find="" the="" estimated="" mean="" sleeping="" time="" and="" the="" standard="" deviation="" (s).="" b)="" find="" the="" margin="" of="" error="" e.="" c)="" construct="" a="" 90%="" confidence="" interval="" based="" on="" the="" same="" data.="" d)="" how="" large="" should="" the="" sample="" be="" if="" you="" want="" to="" be="" 99%="" confident="" that="" the="" estimate="" is="" accurate="" within="" 0.10="" hours="" of="" true="" mean="" of="" sleeping="" time.="" (assume="" o="">