when Caroline runs the 400 m dash, her finishing times are normally distributed with a mean of 68 seconds in a standard deviation of 1.5 seconds. Using the empirical rule, determine the interval of times that represents the middle 99.7% of her finishing times in the 400 m race

Add or subtract polynomial : –12qr? +13rq?

Which is the graph of the function y=2(4)^x

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil