In a survey of 1,208 working Americans it was found that the mean amount of time they spend commuting one-way to work was 48 minutes with a standard deviation of 23 minutes. Construct a 99% confidence interval for the mean length of time Americans spend commuting to work.

What is the value of the discriminant, b2 ? 4ac, for the quadratic equation 0 = x2 ? 4x + 5, and what does it mean about the number of real solutions the equation has?

In may you used 400 kilowatt-hours of energy for electricity. a. calculate the total electrical energy use in joules. b. calculate your average power use in watts. c. assume that your power supplier generates electricity by burning oil. note that 1 liter of oil releases 12 million joules of energy. how much oil is needed to generate the electricity you use? give your answer in both liters and gallons. a. the total electrical energy use was nothing _ joules. (type an integer or a decimal.) b. the average power use is nothing _ watts. (round to the nearest whole number as needed.) c. to generate the electricity you used, nothing _ l is needed. (round to the nearest whole number as needed.) to generate the electricity you used, nothing _ gal is needed. (round to two decimal places as needed.)

Atoss of a 20-sided die is equally likely to be any integer between 1 and 20 inclusive. what is the variance? provide your answer to two decimal points.