9. in how many ways can a 5-question true/false quiz be answered if
it is okay to leave questions unanswered?

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 a 36 inch yardstick casts a 21 foot shadow, how tall is a building whose shadow is 168 feet? what is the scale factor

Idon't get undoing if its pass adding and subtracting so can someone ? x-2 over 5 = 18