hey i found this forum through google. and i am glad i did! everyone in here seems to be helping out a lot. and i would appreciate if someone could help me even though im a new person to the forum but i know for sure i will be using this forum a lot more now! but either way... here are some questions...



1. a supplier of CD's claims that no more than 1% of the disks are defective. in a simple random sample of 300 CD's, it is found that 9 CD's (3%) are defective, but the supplier claims that this high defect rate is only a chance sample fluctuation. at the 0.01 level of significance, test the supplier's claim that no more that 1% are defective.

a. identify the null hypotheses.
b. identify the alternative hypothesis.
c. what is the test statistic?
d. what is the p-value?
e. what is your conclusion about the null hypothesis?
f. what is your conclusion that addresses the original claim in non-technical terms?

2. what is the critical value of X^2 when H1 is sigma > 26.1; n = 22; and alpha = 0.005?

3. assume that the heights of men aged 25 to 34 are normally distributed and have a population standard deviation of 2.9 inches. it is safe to assume that the heights of women are also normally distributed. with a 0.05 significance level, test the claim that the heights of women aged 25 to 34 have a different standard deviation from that of men aged 25 to 34. state your conclusion in non-technical terms and support your conclusion using a method of hypothesis testing we learned in class. the heights (in inches) of 16 randomly selected women aged 25 to 34 are listed below.

62.5, 57.3, 59.5, 69.3, 61.0, 59.8, 59.3, 70.0, 62.3, 58.3, 65.7, 64.8, 66.5, 62.0, 65, 59.5

4. a manufacture supplies ball bearings that are supposed to have a mean weight of 30 g. a customer claims that the mean weight is actually less than 30 g. the mean weight (x-bar) for random sample of 16 ball bearings is 28.5 with a standard deviation (s) of 2.9 g. at the 0.01 significance level, use either the traditional method or the p-value method to test the claim that the mean is less that 30 g. assume that the ball bearings are randomly selected from a population that is normally distributed. state your conclusion in non-technical terms.

5. calculate the (1) test statistic and (2) p-value to test the null hypothesis p1=p2 when a report on the nightly news broadcast stated that 8 out of 1759 households with pet dogs were burglarized and 15 out of 2012 households without pet dogs were burglarized.

test statistic?
p-value?


6. two brands of flares are tested for their burning times (in minutes) and sample results are given below. test the claim that the two populations have equal means, using 0.05 significance level. state your conclusion in non-technical terms. assume that the two samples are independent and that all flares have been randomly selected.

Brand X
n = 76 flares
xbar = 18.5 mins
s = 1.8 mins

brand y
n = 51 flares
xbar = 13.3 mins
s = 0.7 mins



i know like that seems a lot.. but i truly need help on these. this will decide if i pass or fail the class.. thank you so much in advanced.