#5 Test question 7th grade math

The radical equation 2+√2x-3 = √x+7 has a solution set [x= a0} and an extraneous root x = a1.

On saturday morning, calls arrive at ticketmaster at a rate of 108 calls per hour. what is the probability of fewer than three calls in a randomly chosen minute?

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