What is 2+2 and also do u play krunker. io?

The brain volumes (cm cubed) of 50 brains vary from a low of 904 cm cubed to a high of 1488 cm cubed. use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 175.5 cm cubed, assuming the estimate is accurate if it is within 15 cm cubed

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76

Use sigma notation to represent the following series for 9 terms.