Mathematics, 04.12.2019 02:31 Brock2002

Listed below are the lead concentrations in mug/g measured in different traditional medicines. use a 0.01 significance level to test the claim that the mean lead concentration for all such medicines is less than 17 mug/g. 13 21 3.5 18.5 21.5 8.5 15.5 19 9 5 .5

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Answer from: trockout4868

$t=\frac{13.5-17}{\frac{6.57}{\sqrt{10}}}=-1.68$

$p_v =P(t_{(9)}$

If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis.

We can say that at 1% of significance the mean lead concentration for all is significantly less than 17 mug/g.

Step-by-step explanation:

Data given and notation

The mean and sample deviation can be calculated from the following formulas:

$\bar X =\frac{\sum_{i=1}^n x_i}{n}$

$s=\sqrt{\frac{\sum_{i=1}^n (x_i -\bar X)}{n-1}}$

$\bar X=13.5$ represent the sample mean

s=6.57 represent the sample standard deviation

n=10 sample size

$\mu_o =17$ represent the value that we want to test

$\alpha=0.01$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

p_v 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 population mean is less than 17, the system of hypothesis are :

Null hypothesis: $\mu \geq 17$

Alternative hypothesis: $\mu < 17$

Since we don't know the population deviation, is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (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:

$t=\frac{13.5-17}{\frac{6.57}{\sqrt{10}}}=-1.68$

P-value

We need to calculate the degrees of freedom first given by:

df=n-1=10-1=9

Since is a one-side left tailed test the p value would given by:

$p_v =P(t_{(9)}$

Conclusion

If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis.

We can say that at 1% of significance the mean lead concentration for all is significantly less than 17 mug/g.

Answer from: Quest

135 is your answer

step-by-step explanation:

try 180 times three then divide that number by 4 (sides) to get your answer. im glad to : )

Answer from: Quest

Cwill be your correct answer
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