<span>The probability that a randomly selected monthly cell phone bill is more than $127 is given by

$P(X\ \textgreater \ 127)=1-P(X\ \textless \ 127) \\ \\ =1-P\left(z\ \textless \ \frac{127-100}{11.35} \right)=1-P(z\ \textless \ 2.38) \\ \\ =1-0.99132=0.00868$ </span>

5 0

3 years ago

What is the equation of the line that passes through the point (-1,7) and is parallel to the line y= -2x-1

Nuetrik [128]

if we look at the equation y = -2x - 1, is already in slope-intercept form, therefore, $\bf y=\stackrel{slope}{-2}x-1$ has a slope of -2.

now, parallel lines have exactly equal slopes, therefore a parallel to that one above, will have also a slope of -2, so we're really looking for a line whose slope is -2 and runs through -1, 7.

$\bf (\stackrel{x_1}{-1}~,~\stackrel{y_1}{7})\qquad \qquad \qquad slope = m\implies -2\\\\\\\stackrel{\textit{point-slope form}}{y- y_1= m(x- x_1)}\implies y-7=-2[x-(-1)]\\\\\\y-7=-2(x+1)\implies y-7=-2x-2\implies y=-2x+5$

3 0

3 years ago