Question

The commercial for the new Meat Man Barbecue claims that it takes 9 minutes for assembly. A consumer advocate thinks that the assembly time is lower than 9 minutes. The advocate surveyed 13 randomly selected people who purchased the Meat Man Barbecue and found that their average time was 8.5 minutes. The standard deviation for this survey group was 2.3 minutes. What can be concluded at the the αα = 0.10 level of significance level of significance?

1. For this study, we should use Select an answer t-test for a population mean z-test for a population proportion
2. The null and alternative hypotheses would be:

H0:H0:  ? μ p  ? < = ≠ >       

H1:H1:  ? μ p  ? = > < ≠    

3. The test statistic ? z t  =  (please show your answer to 3 decimal places.)
4. The p-value =  (Please show your answer to 4 decimal places.)
5. The p-value is ? ≤ >  αα
6. Based on this, we should Select an answer accept reject fail to reject  the null hypothesis.
7. Thus, the final conclusion is that ...
   • The data suggest the population mean is not significantly lower than 9 at αα = 0.10, so there is statistically insignificant evidence to conclude that the population mean amount of time to assemble the Meat Man barbecue is equal to 9.
   • The data suggest that the population mean amount of time to assemble the Meat Man barbecue is not significantly lower than 9 at αα = 0.10, so there is statistically insignificant evidence to conclude that the population mean amount of time to assemble the Meat Man barbecue is lower than 9.
   • The data suggest the populaton mean is significantly lower than 9 at αα = 0.10, so there is statistically significant evidence to conclude that the population mean amount of time to assemble the Meat Man barbecue is lower than 9.

Answer 1

Ans:

a) t-test for a population mean

b)

c)

Test statistic:

t=(8.5-9)/(2.3/SQRT(13))

t=-0.784

d)p-value=tdist(0.784,12,1)=0.2241

e)p-value>alpha

f)fail to reject  the null hypothesis.

g)

The data suggest that the population mean amount of time to assemble the Meat Man barbecue is not significantly lower than 9 at αα = 0.10, so there is statistically insignificant evidence to conclude that the population mean amount of time to assemble the Meat Man barbecue is lower than 9.