Write the set {x|x is a nonnegative real number} as an interval using interval notation.   I have {x|x is greater than or equal to 0} I just don't know if it's right and unsure if I have to put it on a number line. ​

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?

Atriangular field has sides of lengths 21, 39, and 41 yd. find the largest angle. (round your answer to the nearest degree.)

Onnie is considering doing some long term investing with money that she inherited. she would like to have $50,000 at the end of 30 years. approximately how much money would lonnie need to put into an account earning 6% interest compounded annually in order to meet her goal?