Answer:
Proportions have not changed significantly ( B )
Step-by-step explanation:
GIVEN DATA :
Test statistic = 4.99
significance level = 1% = 0.01
k ( number of groups ) = 3
will we use the chi-squared test to determine the degree of freedom
which is : k-1 = 3 - 1 = 2
looking at the chi-square table to determine the critical value of the test
at significance level = 0.01 and degree of freedom = 2 the critical value = 9.21
Comparing the test value ( 4.99 ) and the critical value ( 9.21 ) it can seen that the test value < critical value which is a condition for not rejecting null hypothesis of the test.
therefore we won't reject the null hypothesis
To solve the system of equations, we first need to isolate one of the variables in one of the equations. For this example, I'll isolate x from the second equation, because it will be much easier and I'll end up with simpler fractions.
2x + y = -3 Given
2x = -y - 3 Subtract y from both sides
x = -1/2y - 3/2
Now, we need to substitute x in the other equation for -1/2y - 3/2 so that we can find y.
3(-1/2y - 3/2) - 7y = 4 Substitute
-3/2y - 9/2 - 7y = 4 Multiply
-17/2y - 9/2 = 4 Collect like terms (wow, this is turning out to be a tough one, isn't it?)
-17/2y = 17/2
y = -1
Wow, such complicated work for such a simple answer. Anyway, now we can plug that into our answer for x to get x's value.
<span>x = -1/2y - 3/2 Given
</span>x = -1/2(-1) - 3/2 Substitute
x = 1/2 - 3/2 Multiply
x = -1 Subtract
Therefore, the solution for the system of equations is (-1,-1). It can be a bit intimidating with all the fractions, but the question decided to be nice and give us simple answers.
Hope this helps!
Here sorry if this doesn't help
