The results of a national survey showed that on average, adults sleep 6.9 hours per night. suppose that the standard deviation is 1.2 hours and that the number of hours of sleep fol- lows a bell-shaped distribution. a. use the empirical rule to calculate the percentage of individuals who sleep between 4.5 and 9.3 hours per day. b. what is the z-value for an adult who sleeps 8 hours per night? c. what is the z-value for an adult who sleeps 6 hours per night?

5 x 14?

im new, sorry if this is wrong.

step-by-step explanation:

  the correct choice is marked

step-by-step explanation:

the first two graphs show multiple turning points. the last graphs matches the description in every detail.

center (1,3) with radius 6

step-by-step explanation:

we must complete the square to find the center and radius of the circle.

first make sure the x and y squared terms have 1 as their coefficients. we also make sure x and y terms together.

we now create space between the x and y terms with parenthesis.

we complete the square by taking the middle terms -2x and the -6y - divide each and square them.

we add the squares to both sides.

simplify.

and write the quadratics in factored form.

the center is (h,k) or (1,3). the radius is the square root of 36 which is 6.