Just found this forum on a search. I am trying to help my son understand statistics, and I am no genius either. He has a homework assignment due Friday that we have both been struggling with. I am looking for someone that might be able to correctly solve the problems so we can check our work against it and possibly use it for guidance on the ones we are stuck on. There are 10 problems and the first 5 are (as far as we are right now) they are as follows:
1. A manufacturer claims that his television will have an average lifetime of at least 5 years (60 months.) The standard deviation is 8 months. 64 sets are selected at random, and their average lifetime was found to be 59 months. Is the manufacturer correct? use ∂=0.025
2. A restaurant in El Paso claims that it will serve a customer lunch in 12 minutes or less or the customer will get lunch free. In order to test this claim, 25 customers kept track of how long it took to get their meal served. Their average time was 13.2 minutes with a standard deviation of 1.5 minutes. At ∂=.01, should the restaurant change its claim?
3. It has been claimed that at O.C.U. at least 35% of the students live on campus. From a sample of 300 students, 98 live on campus. Does the evidence support this claim at ∂ = 0.01?
4. A researcher wanted to determine if there was a difference in the average age of a bride and the average age of a groom. At ∂=.05, test the researcher's claim. A summary of the data is listed below:
X1=24.5 years X2=27.8 years
s1=4.67 years s2=5.16 years
5. A consultant claims that DuraLast batteries are more expensive than EverSet batteries. To est this claim, a consumer organization surveys prices at a large number of stores. The data are summarized as follows:
I'd guess that there's been no replies because of the amount of work involved in explaining how to do each of these questions. Heaps. Especially since the stats ability of your son is a complete unknown.
Each question boils down to hypothesis testing. If your son has no notes or textbook that give examples of these sorts of problems, he might try getting up to speed by working through some of the material available on-line. A google search might get the ball rolling.
Alternatively, if your son posts what work he's done so far on each question, appropriate help can given much more easily and efficiently.