I need help seeing what I did wrong
1 answer:
Answer: The two roots are x = 3/2 and x = -2
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Explanation:
You have the right idea so far. But the two numbers should be 3 and -4 since
- 3*(-4) = -12
- 3+(-4) = -1
The -1 being the coefficient of the x term.
This means you need to change the -3x and 4x to 3x and -4x respectively. The other inner boxes are correct.
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Refer to the diagram below to see one way to fill out the box method, and that helps determine the factorization.
If we place a 2x to the left of -2x^2, then we need an -x up top because 2x*(-x) = -2x^2
Then based on that outer 2x, we need a -2 up top over the -4x. That way we get 2x*(-2) = -4x
So we have the factor -x-2 along the top
The last thing missing is the -3 to the left of 3x. Note how -3*(-x) = 3x in the left corner and -3*(-2) = 6 in the lower right corner.
We have the factor 2x-3 along the left side.
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The two factors are (2x-3) and (-x-2) which leads to the factorization (x+3)(-x+2)
The last thing to do is set each factor equal to 0 and solve for x
- 2x-3 = 0 solves to x = 3/2 = 1.5
- -x-2 = 0 solves to x = -2
The two roots are x = 3/2 and x = -2
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Answer:
p ( x > 2746 ) = p ( z > - 1.4552 )
= 1 - 0.072806
= 0.9272
This shows that there is > 92% of a republican candidate winning the election hence I will advice Gallup to declare the Republican candidate winner
Step-by-step explanation:
Given data:
51% of male voters preferred a Republican candidate
sample size = 5490
To win the vote one needs ≈ 2746 votes
In order to advice Gallup appropriately lets consider this as a binomial distribution
n = 5490
p = 0.51
q = 1 - 0.51 = 0.49
Hence > 5 while
< 5
we will consider it as a normal distribution
From the question :
number of male voters who prefer republican candidate ( mean ) ( u )
= 0.51 * 5490 = 2799.9
std = =
= 37.0399 ---- ( 1 )
determine the Z-score = (x - u ) / std ---- ( 2 )
x = 2746 , u = 2799.9 , std = 37.0399
hence Z - score = - 1.4552
hence
p ( x > 2746 ) = p ( z > - 1.4552 )
= 1 - 0.072806
= 0.9272
This shows that there is > 92% of a republican candidate winning the election hence I will advice Gallup to declare the Republican candidate winner
Answer:
Since is a right tailed test the p value would be:
Comparing the p value with the significance level we see that
so we can conclude that we have enough evidence to reject the null hypothesis, and the mean for group 1 is significantly higher than the mean for the group 2
Step-by-step explanation:
Data given
represent the mean for sample 1
represent the mean for sample 2
represent the sample standard deviation for 1
represent the sample standard deviation for 2
sample size for the group 2
sample size for the group 2
Significance level provided
t would represent the statistic (variable of interest)
Concepts and formulas to use
We need to conduct a hypothesis in order to check if the mean for category 1 is higher than the mean for category 2, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
We don't have the population standard deviation's, so for this case is better apply a t test to compare means, and the statistic is given by:
(1)
And the degrees of freedom are given by
t-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.
With the info given we can replace in formula (1) like this:
P value
Since is a right tailed test the p value would be:
Comparing the p value with the significance level we see that
so we can conclude that we have enough evidence to reject the null hypothesis, and the mean for group 1 is significantly higher than the mean for the group 2