To estimate the mean score μ μ of those who took the medical college admission test on your campus, you will obtain the scores of an srs of students. from published information you know that the scores are approximately normal with standard deviation about 6.6 6.6 . you want your sample mean ¯ x x¯ to estimate μ μ with an error of no more than 1.1 1.1 point in either direction. (a) what standard deviation must ¯ x x¯ have so that 99.7 % 99.7% of all samples give an ¯ x x¯ within 1.1 1.1 point of μ μ ? use the 68 – 95 – 99.7 68–95–99.7 rule. (enter your answer rounded to four decimal places.) standard deviation of ¯ x = x¯= (b) how large an srs do you need in order to reduce the standard deviation of ¯ x x¯ to the value you found? (enter your answer rounded to the nearest whole number.) srs size =

Delbert keeps track of total of the total number of points he earns on homework assignments, each of which is worth 60 points. at the end of the semester he has 810 points. write an equation for delbert’s average homework score a in terms of the number of assignments n.

The line plot below represents the number of letters written to overseas pen pals by the students at the waverly middle school. each x represents 10 students. how many students wrote more than 6 and fewer than 20 letters. a.250 b.240 c.230 d.220

Suppose that a customer is purchasing a car. he conducts an experiment in which he puts 10 gallons of gas in the car and drives it until it runs out of gas. he conducts this experiment 15 times on each car and records the number of miles driven. full data set car 1 238238 216216 205205 212212 240240 274274 297297 252252 260260 247247 257257 243243 296296 243243 290290 car 2 245245 204204 215215 209209 251251 165165 221221 295295 172172 287287 268268 305305 320320 260260 297297 describe each data set, that is determine the shape, center, and spread. sample mean for car 1 x overbar equalsx=216216 mi / 10 gal (type an integer or decimal rounded to one decimal place as needed.) sample mean for car 2 x overbar equalsx=209209 mi / 10 gal (type an integer or decimal rounded to one decimal place as needed.)