Rewrite the following expression with rational exponents. 3 sq root -27x^2 y^7 Show your work
1 answer:
Answer:
Step-by-step explanation:
The square root is possible only if y≤0
if y>0 the expression lose meaning, in fact (-)(+)(+) = (-) and a square root of a negative number doesn’t exist. x^2 is a square so it is ever positive if x is not 0
if y≤0 can be rewritten as:
3(-27x^2y^7)^1/2
or if we want simplify the expression:
^1/2
we have to put the symbol of absolute value between x and y because a x^2 and y^6 are numbers that are ever positive, while x and y^3 can be also negative. Thanks to the simbol of absolute value we can “force” them to be positive
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Answer:
P-value (t=2.58) = 0.0066.
Note: as we are using the sample standard deviation, a t-statistic is appropiate instead os a z-statistic.
As the P-value (0.0066) is smaller than the significance level (0.05), the effect is significant.
The null hypothesis is rejected.
There is enough evidence to support the claim that the population mean μ exceeds 2.4.
Step-by-step explanation:
This is a hypothesis test for the population mean.
The claim is that the population mean μ exceeds 2.4.
Then, the null and alternative hypothesis are:
The significance level is 0.05.
The sample has a size n=45.
The sample mean is M=2.5.
As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=0.26.
The estimated standard error of the mean is computed using the formula:
Then, we can calculate the t-statistic as:
The degrees of freedom for this sample size are:
This test is a right-tailed test, with 44 degrees of freedom and t=2.58, so the P-value for this test is calculated as (using a t-table):
As the P-value (0.0066) is smaller than the significance level (0.05), the effect is significant.
The null hypothesis is rejected.
There is enough evidence to support the claim that the population mean μ exceeds 2.4.