A biologist wants to estimate the difference between the mean body lengths of green and browns stunk bugs. A random sample of 20 green stinkbugs has a mean body length of 16.22 mm and a standard devotion of 1.34 mm. A random sample of 20 brown stinkbugs has a mean body length of 13.41 mm and a standard deviation of .73 mm. What is the standard error of difference between sample means?

The sat and act tests use very different grading scales. the sat math scores follow a normal distribution with mean 518 and standard deviation of 118. the act math scores follow a normal distribution with mean 20.7 and standard deviation of 5. suppose regan scores a 754 on the math portion of the sat. how much would her sister veronica need to score on the math portion of the act to meet or beat regan's score?

If the value of cos330°is√3/2 then find cos 165°.

The data set represents the ages of players in a chess club. 27, 34, 38, 16, 22, 45, 54, 60. what is the mean absolute deviation of the data set?