Find the area under the standard normal curve to the left of z=−2.94 and to the right of z=−2.28. round your answer to four decimal places, if necessary.

The area under the standard normal curve to the left of z=−2.94 and to the right of z=−2.28 is 0.9903 square units.

Step-by-step explanation:

We need to find the area under the standard normal curve to the left of z=−2.94 and to the right of z=−2.28.

The standard normal table represents the area under the curve.

         .....(1)

According to the standard normal table, we get

Substitute these values in equation (1).

Therefore the area under the standard normal curve to the left of z=−2.94 and to the right of z=−2.28 is 0.9903 square units.

The total cost for television company number 1 expressed as a function of x is

c1(x)=11.5x+120

That is the charge per month the number of hours plus the fixed charge for a one-time installation

Using the same pattern, write the function for the second television company. Then set the two functions equal to each other and solve for x.