(7x+3)-(2x+1) how would you subtract this
1 answer:
You might be interested in
Answer:
Step-by-step explanation:
From this study:
The null hypothesis:
The altenative is:
This test is a two-tailed test.
However; we are told that the wives have 44 success out of 66, then the number of failures will be 22.
Then;
Similarly, the husbands have 18 success out of 46, then the number of failures will be 28
Then:
The pooled proportion
p = 0.55357
The estimated standard error S.E is:
=
= 0.0955
The Z test statitics can now be computed as:
Z = 2.88
Th p -value from the test statistics is:
p-value = 2P(Z > 2.88)
p- value = 2 P (1 - Z < 2.88)
p-value = 2 ( 1 - 0.998)
p-value = 2 ( 0.002)
p -alue = 0.004
Decision Rule:
Thus, at 0.01 significance level, we reject the null hypothesis because, p-value is less than that (i.e. significance level)
Conclusion:
We conclude that there is a significant difference between the proportions.
<h3>Answer: 2 feet</h3>
========================================================
Explanation:
x = width of the walkway in feet
This is some positive real number.
The dimension of 20 feet bumps up to 20+2x when adding on x from both directions. Similarly, the 40 ft dimension becomes 40+2x
Refer to the diagram below.
The 20 ft by 40 ft pool is surrounded by a larger rectangle that is 20+2x ft by 40+2x ft
The pool itself is 20*40 = 800 sq ft. Add on the walkway area to get 800+256 = 1056 sq ft.
-----------
Area = length*width
1056 = (20+2x)*(40+2x)
1056 = 20*40 + 20*2x + 2x*40 + 2x*2x ... FOIL rule
1056 = 800 + 40x + 80x + 4x^2
0 = 4x^2 + 40x + 80x + 800 - 1056
0 = 4x^2 + 120x - 256
4x^2 + 120x - 256 = 0
4(x^2 + 30x - 64) = 0
x^2 + 30x - 64 = 0
Let's use the quadratic formula to finish solving for x.
Plug in a = 1, b = 30, c = -64
Recall we made x be positive. This is because a negative walkway width does not make sense. This means we'll ignore x = -32.
The only practical solution is x = 2
Therefore, the walkway is <u>2 feet wide</u>