Answer: (7.27%, 7.55%)
Step-by-step explanation:
As per given , we have
Sample size : n= 392
Sample mean :
Critical two-tailed z-value for 95% confidence =
Required confidence interval would be :
Hence, the required 95% confidence interval for the mean percentage share of billing volume from network television for the population of all U.S. advertising agencies : (7.27%, 7.55%)
The absolute value equation is , if the solutions are x=2.5 and x=-3.5.
Step-by-step explanation:
The given is,
Two solutions: x = 2.5 and x = -3.5
Step:1
In this question we use reverse method of quadratic equation solve method,
From first solution, x = 2.5
x - 2.5 = 0..........................(1)
From the second solution, x = -3.5
x + 3.5 = 0.................(2)
From the equations (1) and (2),
( x - 2,5 ) ( x + 3.5 ) = 0
Multiply the equations,
Step:2
Check for solution,
..........................(3)
Substitute the value of x=2.5 in above equation,
6.25 + 2.5 - 8.75 = 0
0 = 0
Result:
The absolute value equation is , if the solutions are x=2.5 and x=-3.5.