Martin finds a shirt on sale for 10% off at a department store. The original price was $20. Martin must also pay $8.5% sales tax
1 answer:
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Answer:
c. ax+b=ax+b
Step-by-step explanation:
To know what equation has infinite solutions, you first try to simplify the equations:
a.
In this case you have that a must be different of b, but there is no restriction to the value of c, then c can be equal to a or b.
b.
Here you obtain that b = c. But the statement of the question says that a, b and c are three different numbers.
c.
In this case you have that whichever values of a, b and are available solutions of the equation. Furthermore, when you obtain 0=0, there are infinite solutions to the equation.
Then, the answer is:
c. ax+b=ax+b
Answer:
If we compare the p value and the significance level assumed of 0.05 we see that so on this case we have enough evidence in order to reject the null hypothesis at the significance level provided. And that means that the population variance is significantly higher than 0.26^2=0.0676.
Step-by-step explanation:
Notation and previous concepts
A chi-square test is "used to test if the variance of a population is equal to a specified value. This test can be either a two-sided test or a one-sided test. The two-sided version tests against the alternative that the true variance is either less than or greater than the specified value"
represent the sample size
represent the confidence level
represent the sample variance obtained
represent the value that we want to test
Null and alternative hypothesis
On this case we want to check if the population variance specification is violated, so the system of hypothesis would be:
Null Hypothesis:
Alternative hypothesis:
Calculate the statistic
For this test we can use the following statistic:
And this statistic is distributed chi square with n-1 degrees of freedom. We have eveything to replace.
Calculate the p value
In order to calculate the p value we need to have in count the degrees of freedom , on this case df=15-1=14. And since is a right tailed test the p value would be given by:
In order to find the p value we can use the following code in excel:
"=1-CHISQ.DIST(31.5,14,TRUE)"
Conclusion
If we compare the p value and the significance level assumed of 0.05 we see that so on this case we have enough evidence in order to reject the null hypothesis at the significance level provided. And that means that the population variance is significantly higher than 0.26^2=0.0676.