The nutrition label on a bag of potato chips says that a one ounce (28 gram) serving of potato chips has 130 calories and contains ten grams of fat, with three grams of saturated fat. A random sample of 35 bags yielded a sample mean of 134 calories with a standard deviation of 17 calories.
a. Is there evidence that the nutrition label does not provide an accurate measure of calories in the bags of potato chips?
b. State your null and alternative hypotheses, your computed p-value, and your decision based on the given random sample.

Respuesta :

Answer:

a) For this case we don't have enough evidence to conclude that the nutrition label provides does not an accurate measure since we fail to reject the null hypothesis on this case.

b) Null hypothesis:[tex]\mu = 130[/tex]  

Alternative hypothesis:[tex]\mu \neq 130[/tex]  [tex]t=\frac{134-130}{\frac{17}{\sqrt{35}}}=1.39[/tex]    

[tex]p_v =2*P(t_{(34)}>1.39)=0.1735[/tex]  

If we compare the p value and the significance level assumed [tex]\alpha=0.05[/tex] we see that [tex]p_v>\alpha[/tex] so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the height of men actually its significant different from 130 at 5% of signficance.  

Step-by-step explanation:

Data given and notation  

[tex]\bar X=134[/tex] represent the sample mean

[tex]s=17[/tex] represent the sample standard deviation

[tex]n=35[/tex] sample size  

[tex]\mu_o =130[/tex] represent the value that we want to test

[tex]\alpha[/tex] represent the significance level for the hypothesis test.  

t would represent the statistic (variable of interest)  

[tex]p_v[/tex] 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 130 or not, the system of hypothesis would be:  

Null hypothesis:[tex]\mu = 130[/tex]  

Alternative hypothesis:[tex]\mu \neq 130[/tex]  

If we analyze the size for the sample is > 30 but we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:  

[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex]  (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:  

[tex]t=\frac{134-130}{\frac{17}{\sqrt{35}}}=1.39[/tex]    

P-value

The first step is calculate the degrees of freedom, on this case:  

[tex]df=n-1=35-1=34[/tex]  

Since is a two sides test the p value would be:  

[tex]p_v =2*P(t_{(34)}>1.39)=0.1735[/tex]  

Conclusion  

If we compare the p value and the significance level assumed [tex]\alpha=0.05[/tex] we see that [tex]p_v>\alpha[/tex] so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the height of men actually its significant different from 130 at 5% of signficance.