7x+3-5x+8+4x-1 i need help with this
2 answers:
We are trying to simplify the expression 7x+3-5x+8+4x-1
Simplify by like terms- like terms are numbers with the same variable to the same degree (ex. 5x and 28x, and
, 3xy and 9xy) and also all constants are like terms (normal numbers ex. 9, 189, 3, -2)
So lets rearrange this equation
7x-5x+4x+3+8-1
Remember to bring along the negative or positive sign (don't think it as subtracting 5x, think of it as negative 5x)
All the numbers with x are like terms and a constants are like terms. So combine.
6x+10 is the simplified expression
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Answer:
If we compare the p value and the 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 true mean is higher than 12 at 5% of signficance.
Step-by-step explanation:
Data given and notation
represent the sample mean
represent the population standard deviation for the sample
sample size
represent the value that we want to test
represent the significance level for the hypothesis test.
z 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 conduct a hypothesis in order to check if the mean is equal to 12, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
Since we know the population deviation, is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:
(1)
z-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:
P-value
Since is a right tailed test the p value would be:
Conclusion
If we compare the p value and the 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 true mean is higher than 12 at 5% of signficance.