Help please. KHAN ACADEMY!!!

1-for what value of x is line a parallel to line b 2-for what value of x is line a parallel to line b

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

The quadratic function h(t)=-16.1t^2+150 choose the graph representation