The sales data from the past two months of a frozen yogurt shop are approximately normal. The mean daily sales for the first month was $200 with a standard deviation of $30. On the 15th of the first month, the shop sold $245 of yogurt. The mean daily sales for the second month was $220 with a standard deviation of $50. On the 15th of the second month, the shop sold $270 of yogurt. Which month had a higher z-score for sales on the 15th, and what is the value of that z-score? a.) The second month, with a z-score of 1. b.) The second month, with a score of 1.67. c.) The first month, with a score of 0.9. d.) The first month, with a z-score of 1.5.

The  correct option is D

Step-by-step explanation:

From the question we are told that  

     The mean for the first month is  

       The standard deviation for first month is

       The  sale on 15th of  first month is  

       The mean for the second  month is

         The standard deviation for second month is

         The  sale on 15th of  second month is

Generally the z-score is mathematically represented as

For the  first month  

For the second  month

(0,-3) see attached graph

step-by-step explanation:

a. to solve the system, graph the two equations.

x = y+3 becomes y=x-3 has m=1/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move up 1 unit and 1 unit to the right. plot a point and connect.

y=-4x+3 has m =-4/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move down four units and to the right 1 unit. plot a point and connect.

the solution is the point (x,y) where the two lines intersect. by the graph below it is (0,-3).

b. to solve by substitution, substitute y = -4x-3 into x= y+3

x= (-4x-3) +3

x=-4x

5x=0

x=0

now substitute x = 0 back in to find y.

y= -4(0)-3

y=0-3

y=-3

solution is (0,-3)

c. use elimination by adding the equations together.

x-y=3

4x+y=-3

5x=0

x=0

then substitute into one equation to find y.

y=-4(0)-3

y=-3

heudhduxhdnshenebdutbbt

step-by-step explanation:

hrhhdhdbbrurb ees