1. The author’s of the article “Perceived risks of Heart Disease and Cancer Among Cigarette Smokers” expressed the concern that a majority of smokers do not view themselves as being at increased risk of heart disease or cancer. Because of this, the authors call for a public health campaign to educate smokers about the associated risks. In support of this recommendation, the authors offered the results of a study of 737 current smokers selected at random from the U.S. households with telephones. Of the 737 smokers surveyed, 295 indicated that they believe that they have a higher then average risk for cancer. Does this data suggest that the true proportion of smokers who view themselves as being at increased risk of cancer is, in fact, less than 0.5 as claimed by the authors of the paper?
p0 = pop. proportion; p = sample proportion (since I cannot type in p-hat)
2. Many consumers pay careful attention to stated nutritional contents on packaged foods when making purchases. It is therefore important that the information on the packages is accurate. The stated calorie count of a particular frozen dinner is 240. A random sample of 12 frozen dinners of the same type was selected from production and the calorie content of each one was determined. Is there significant evidence at the 5% level that the mean calorie count is higher than the stated 240 calories? The following observations are the results of the testing:
255 244 239 242 265 245 259 248 225 226 251 233
3. Much concern has been expressed in recent years regarding the practice of using nitrates as meat preservatives. In one study involving the possible effects of these chemicals, bacteria cultures were grown in a medium containing nitrates. The rate of uptake of radio-labeled amino acid was then determined for each one, yielding the following observations: 7251 6871 9632 6866 9094 5849 8957 7978 7064 7494 7883 8178 7523 8724 7468
Suppose it is known that the true average uptake for cultures without nitrates is 8000. Does the data suggest at the 1% level of significance, that the addition of the nitrates results in a decrease in true average uptake?
4. An automobile manufacturer who wishes to advertise that one of its models achieves 30 miles per gallon decides to carry out a fuel efficiency test. Six non- professional drivers are selected. Each one drives a car from Phoenix to Los Angeles. The resulting mile per gallon figures are: 27.2 29.3 31.2 28.4 30.3 29.6
Does the data contradict the claim that the true average fuel efficiency is 30mpg? Test this at the 1% level of significance.