6. A pencil costs $2 less than a notebook. A pen costs 3 times as much as a pencil. The pen costs $9. Write and solve an equation to determine the cost of the notebook and the cost of the
pencil.

Cor d? ? me ? max recorded the heights of 500 male humans. he found that the heights were normally distributed around a mean of 177 centimeters. which statements about max’s data must be true? a) the median of max’s data is 250 b) more than half of the data points max recorded were 177 centimeters. c) a data point chosen at random is as likely to be above the mean as it is to be below the mean. d) every height within three standard deviations of the mean is equally likely to be chosen if a data point is selected at random.

Find the volume v of the solid obtained by rotating the region bounded by the given curves about the specified line. y = x â’ 1 , y = 0, x = 5; about the x-axis v = sketch the region. sketch the solid, and a typical disk or washer.

Me because i don't understand how to do it.: )