Answer:
Step-by-step explanation: add the equations
2x² = 30
x² = 15
y² = 12 - 15
= -3
x4 -y4 = 15² - (-3)²
= 216
Answer: 5.37
Step-by-step explanation:
Let x = ACT scores.
Given: ACT scores have a mean of 20.8 and 9 percent of the scores are above 28. The scores have a distribution that is approximately normal.
i.e. P(X>28)=0.09 (i)
Now,
(ii)
One -tailed z value for p-value of 0.09 =1.3408 [By z-table]
From (i) and (ii)

Hence, the standard deviation = 5.37
I got 20,737 but I could be wrong so I will attach my algorithm and work.
Answer:
56,000
Step-by-step explanation: