4.5 is the answer because I think you just subtract the two numbers that is given. Because they is asking for the difference
3x + 6y = 18 -6y
3x = 18 - 6y Divide by 3
3x/3=18/3-6y/3 Simplify
x=6-2y
Now we check by plugging in the value of x.
3(6-2y)+6y=18 simplify
18-6y+6y=18 simplify more
18=18.
NOW we know for sure that this is correct
x=6-2y
Let K = km in 7 weeks
Equation:
K = 7(20)
Answer:
Given:
Null hypothesis: the average salary for new college graduates with a job is $50,556.
Alternative hypothesis: the graduates from a university earn more than that average.
Using the z-test:
=> Calculate the value of test statistic:
t = (mean of sample - mean of null hypothesis)/(std/sqrt(number of sample)
= (53200 - 50556)/(10200/sqrt(100))
= 2.592 > 1.645
=> Reject the null hypothesis, their graduates earn more than average
Hope this helps!
:)