# testing the difference between two means

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• Aug 25th 2007, 03:47 PM
mkcar
testing the difference between two means
Hi, I need some help, In the problem I'm to A. identify the claim and state Ho and Ha, B. find the critical value(s0 and identify the rejection region(s), C. find the stndardized test statistic z, D. decide whether to reject or fail to reject the null hypothesis and e. interpret the decision in the context of the original claim.

The exercise the problem is to refer to is this..
#16. A restaurant association says that households in the United States headed by people under the age of 25 spend less on food away from home than households headed by peopl ages 55-64. The mean amount spent by 30 households headed by people under the age of 25 is $1526 and the standard deviation is$225. The mean amount spent by 30 households headed by people 55-64 is $2136 and the standard deviation is$350. Can you support the restaurant association's claim at a= 0.05?

Now the question that I have to do is this
Refer to exercise #16. Two more samples are taken, one from each age group. For 40 households headed by people under the age 25, X-bar1-$1600 and s1=$230. For 40 households headed by people ages 55-64, x-bar2= $2040 and S2 =$380 . Use a = 0.05 . I have to do the problem then see if the new samples lead to a different conclusion?

I'm confused over this word problem, any help would be great.
• Aug 25th 2007, 04:26 PM
TKHunny
Tests of Hypotheses often are quite unsatisfying, mostly because the beginning student has no sense of accomplishment. It is a very common thing to hear, "That's it?" at the end of the investigation. No worries. Just go through the steps.

$H_{0}$ is your claim. In this case, something like $\mu_{55} - \mu_{25} > 0$

You tell me what the Alternate Hypothesis is.

Once you have that, how does one compare two independent and normally distributed means?