Answer:
Step-by-step explanation:
Assuming conditions are met, the formula for a confidence interval (CI) for the difference between two population proportions is 
where 
and 
are the sample proportion and sample size of the first sample, and 
and 
are the sample proportion and sample size of the second sample.
We see that 
and 
. We also know that a 98% confidence level corresponds to a critical value of 
, so we can plug these values into the formula to get our desired confidence interval:
Hence, we are 98% confident that the true difference in the proportion of people that live in a city who identify as a democrat and the proportion of people that live in a rural area who identify as a democrat is contained within the interval {-0.2941,-0.0337}
The 98% confidence interval also suggests that it may be more likely that identified democrats in a rural area have a greater proportion than identified democrats in a city since the differences in the interval are less than 0.
Answer:
80
Step-by-step explanation:
25% of 80 is 20
20 x 4 = 80
27x^2-81x-9x+27 In this case, just in your mind multiply 27 (coefficient of x^2) by the constant value 27(the end value of the quadratic trinomial). Then find factors that give you the value -90 when you add and 729 (27*27) when you multiply.
Factorise the values
27x( x-3)-9(x-3)
Which will give you
(27x-9)(x-3)
Answer:
(2, -6)
Step-by-step explanation:
5n^2+20n-60
(5n+30)(n-2)
5n + 30 = 0
5n = -30
(5n = -30)/5
n = - 6
n - 2 = 0
n = 2
answer: (2, -6)
The answer is 12 m.
How to solve:
First find out the height of the bottom square, which is done by doing 3 x 3 which gives you 9
Next find out the height of the triangle by doing 5 - 3 which gives you 2
Find out the area of the triangle by doing 2 x 3 which gives you 6. 6 is not the area of one triangle but of two of them as a square. You need to divide 6 by 2 in order to find out the area of the triangle. This gives you 3.
3 + 9 = 12
