Kevin, Lakita, and Oscar work for a housekeeping company. Kevin can complete a regular job at a customer’s residence in 3 hours 50 minutes if he works alone. Lakita can complete the job in 4 hours 40 minutes if she works alone. One day Kevin, Lakita, and Oscar are all assigned to the job. Kevin and Lakita begin working at 1:00 P. M. Oscar arrives later and begins working at 1:20 P. M. They all complete the job at 2:20 P. M. How many minutes does it take Oscar to complete the job if he works alone? (Assume they all work at steady rates and their rates are not affected by either working alone or working together.)

The table shows population statistics for the ages of best actor and best supporting actor winners at an awards ceremony. the distributions of the ages are approximately bell-shaped. compare the z-scores for the actors in the following situation. best actor best supporting actor muequals42.0 muequals49.0 sigmaequals7.3 sigmaequals15 in a particular year, the best actor was 59 years old and the best supporting actor was 45 years old. determine the z-scores for each. best actor: z equals best supporting actor: z equals (round to two decimal places as needed.) interpret the z-scores. the best actor was (more than 2 standard deviations above more than 1 standard deviation above less than 1 standard deviation above less than 2 standard deviations below) the mean, which (is not, is) unusual. the best supporting actor was (less than 1 standard deviation below more than 1 standard deviation above more than 2 standard deviations below more than 1 standard deviation below) the mean, which (is is not) unusual.

1- is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis. 2- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis. 3- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in part b?

How do you write something in scientific notation?