Aresearcher in a small midwestern town wants to estimate the mean weekday sleep time of its adult residents. he takes a random sample of 40 adult residents and records their weekday average sleep time as 6.4 hours. the researcher knows that the population standard deviation is 1.8 hours.
what is the lower confidence limit (lcl) of the 95% confidence interval for the mean weekday sleep time of all adult residents of this midwestern town? round your answer to 2 decimal places.

Logan wants to know how many skateboards have defective parts. he inspects 20,000 skateboards and keeps track of the number of defects per board. use his probability distribution table to find the expected value for defects on a skateboard.

The avenues in a particular city run north to south and are numbered consecutively with 1st avenue at the western border of the city. the streets in the city run east to west and are numbered consecutively with 1st street at the southern border of the city. for a festival, the city is not allowing cars to park in a rectangular region bordered by 5th avenue to the west. 9th avenue to the east, 4th street to the south, and 6th street to the north. if x is the avenue number and yis the street number, which of the following systems describes the region in which cars are not allowed to park? 5th ave 9th ave

The function v(r)=4/3pir^3 can be used to find the volume of air inside a basketball given its radius. what does v(r) represent