if you meant x^2+9x+20 then it is (x+4)(x+5) you know that because 4+5=9 and 4x5=20 using FOIL
Silva set up a dog-walking business. He earned $60 in June. He is projected to earn 110% more in July. How much is Silva project
1 answer:
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Answer:
If we compare the p value and a significance level given we see that
so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the population mean is signficantly higher than 83.2 at 1% of significance.
Step-by-step explanation:
Data given and notation
represent the average life for the sample
represent the population standard deviation
sample size
represent the value that we want to test
represent the significance level for the hypothesis test.
t would represent the statistic (variable of interest)
represent the p value for the test (variable of interest)
State the null and alternative hypotheses.
We need to apply a two tailed test.
What are H0 and Ha for this study?
Null hypothesis:
Alternative hypothesis :
Compute the test statistic
The statistic for this case is given by:
(1)
t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".
Calculate the statistic
We can replace in formula (1) the info given like this:
Give the appropriate conclusion for the test
First we need to calculate the degrees of freedom given by:
Since is a one side right tailed test the p value would be:
Conclusion
If we compare the p value and a significance level given we see that
so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the population mean is signficantly higher than 83.2 at 1% of significance.
Answer:
And we can assume a normal distribution and then we can solve the problem with the z score formula given by:
And replacing we got:
We can find the probability of interest using the normal standard table and with the following difference:
Step-by-step explanation:
Let X the random variable who represent the expense and we assume the following parameters:
And for this case we want to find the percent of his expense between 38.6 and 57.8 so we want this probability:
And we can assume a normal distribution and then we can solve the problem with the z score formula given by:
And replacing we got:
We can find the probability of interest using the normal standard table and with the following difference: