Consider results of 20 randomly chosen people who have run a marathon. Their times, in minutes, are as follows: 136, 143, 152, 165, 171, 178, 184, 195, 196, 205, 219, 221, 232, 239, 256, 267, 275, 281, 284, 289. Calculate a 95% upper confidence bound on the mean time of the race. Assume distribution to be normal. Round your answer to the nearest integer (e. g. 9876).

Write an explicit formula that represents the sequence defined by the following recursive formula:

Mary beth used the mapping rule to find the coordinates of a point that had been rotated 90° counterclockwise around the origin. examine the steps to determine whether she made an error. m (3, –6) is rotated 90° counterclockwise. (x, y) → (–y, x) 1. switch the x- and y-coordinates: (6, –3) 2. multiply the new x-coordinate by –1: (6(–1), –3) 3. simplify: (–6, –3) .

Colby and jaquan are growing bacteria in an experiment in a laboratory. colby starts with 50 bacteria in his culture and the number of bacteria doubles every 2 hours. jaquan starts with 80 of a different type of bacteria that doubles every 3 hours. let x equal number of days. colbys experiment follows the model: a.) y=50*2^x b.) y=50*2^8x c.) y=50*2^12x jaquans experiment follows the model: a.)80*2^x b.)80*2^8x c.)80*2^12x