Answer:
The claim is rejected
Step-by-step explanation:
Claim: UCF is advertising their bachelor in Economics with the statistic that the starting salary of a graduate with a bachelor in economics is $ 48,500 according to Payscale (2013-13).
Null hypothesis: 
Alternate hypothesis :
n = 50
Since n is more than 30 .
So we will use Z test
x=43350
Standard deviation = 15000

Refer the z table
p value = 0.00776

p value < 
So, We are failed to accept null hypothesis
Hence The claim is rejected
Answer:
(6-√21, 6+√21)
Step-by-step explanation:
x^2 - 12x = -15
(x - 6)^2 - 36 = -15
(x - 6)^2 = 21
x - 6 = ± √21
x = 6 ± √21
The answer is 4000 because the value of 4 is 40000 so times that by 1/10 gives you 4000