The file P08_23.xlsx contains data from a survey of 500 randomly selected households. a. Separate the households in the sample by the location of their residence within the given community. For each of the four locations, use the sample information to calculate a 90% confidence interval for the mean annual income (sum of first income and second income) of all relevant households. Round your answers to the nearest whole dollar, if necessary.

Total income SW Sector NW Sector NE Sector SE Sector

Lower Limit $

$

$

$

Upper Limit $

$

$

$

Acable company wants to provide cell phone service for residents on an island. the function for the cost of laying the cable from the island to the mainland is c(x)= 6.500 square root x2+4, where x represents the length of the cable in feet. what are the domain and range of the function? a) domain: all real numbers range: all real numbers greater than or equal to 17,000 b) domain: all real numbers greater than or equal to 0 range: all real numbers greater than or equal to 17,000 c) domain: all real numbers greater than or equal to 0 range: all real numbers greater than or equal to 13,000 d) domain: all real numbers greater than or equal to 13,000 range: all real numbers greater than or equal to 0

Aculture started with 3000 bacteria. after 5 hours it grew to 3900 bacteria. predict how many bacteria will be present after 9 hours

Use the quadratic formula to solve the equation. if necessary, round to the nearest hundredth. x^2 - 23 = 10x a. -1.93, 11.93 b. 1.93, -11.93 c. 1.93, 11.93 d. -1.93, -11.93