A psychologist is studying the self image of smokers, as measured by the self-image (SI) score from a personality inventory. She would like to examine the mean SI score,  μ , for the population of all smokers. Previously published studies have indicated that the mean SI score for the population of all smokers is  80  and that the standard deviation is  12 , but the psychologist believes that the value for the mean has decreased. She plans to perform a statistical test. She takes a random sample of SI scores for smokers and computes the sample mean to be  74 . Based on this information, answer the questions below. What are the null hypothesis ( H0 ) and the alternative hypothesis ( H1 ) that should be used for the test? H0 :  μ  is ?less thanless than or equal togreater thangreater than or equal tonot equal toequal to ?748012 H1 :  μ  is ?less thanless than or equal togreater thangreater than or equal tonot equal toequal to ?748012 In the context of this test, what is a Type I error? A Type I error is ?rejectingfailing to reject the hypothesis that  μ  is ?less thanless than or equal togreater thangreater than or equal tonot equal toequal to ?748012 when, in fact,  μ  is ?less thanless than or equal togreater thangreater than or equal tonot equal toequal to ?748012. Suppose that the psychologist decides not to reject the null hypothesis. What sort of error might she be making? ?Type IType II

In this exercise, you will compare Chebyshev’s rule and the empirical rule. a. Compare the estimates given by the two rules for the percentage of observations that lie within two standard deviations to either side of the mean. Comment on the differences.b. Compare the estimates given by the two rules for the percentage of observations that lie within three standard deviations to either side of the mean. Comment on the differences.

A distribution of scores has no mode and the same median and mean values. This indicates that the

You are comparing data from two similar experiments that have a mean of 53. Experiment A has a standard deviation of 3.4 and experiment B has a standard deviation of 1.5. What does this tell you about the data in the experiments?

There are two major tests of readiness for college, the ACT and the SAT. ACT scores are reported on a scale from 1 to 36. The distribution of ACT scores is approximately Normal, with mean of 21.2 and standard deviation of 5.2, SAT scores are reported on a scale from 400 to 1600. The distribution of SAT scores is approximately Normal, with mean of 1,159 and standard deviation of 205. What ACT scores make up the top 10% of all the scores? Round to the nearest whole number. 80 888 #3 $ & 3 4. 7 E Y U F G H J K DI

The average McDonald's restaurant generates $3.1 million in sales each year with a standard deviation of 0.4. Micah wants to know if the average sales generated by McDonald's restaurants in Maryland is different than the worldwide average. He surveys 19 restaurants in Maryland and finds the following data (in millions of dollars):2.8, 3.2, 3.8, 4.2, 3.5, 3.2, 3.6, 3.2, 2.7, 3.1, 2.5, 3.2, 3.7, 3.5, 3.9, 3.9, 2.5, 2.9, 2.8Perform a hypothesis test using a 9% level of significance.Step 1: State the null and alternative hypotheses.H0:H0:             Ha:Ha:             (So we will be performing a      test.)Step 2: Assuming the null hypothesis is true, determine the features of the distribution of point estimates using the Central Limit Theorem.By the Central Limit Theorem, we know that the point estimates are     with distribution mean  and distribution standard deviation .Step 3: Find the pp-value of the point estimate.P(P(        )=P()=P(        )=)=pp-value==Step 4: Make a Conclusion…

A study reported on essential organic molecules and a Normal model can be used to describe these levels in adults. If the mean is 194 mg/dL and a standard deviation is 28​, complete the following questions.   a) Draw and label the Normal model.   ​b) What percent of adults do you expect to have this essential organic​ molecule, cholesterol, levels over 210 mg/dL?   ​c) What percent of adults do you expect to have cholesterol levels between 150 and 170 ​mg/dL?   ​d) Estimate the interquartile range of cholesterol levels.   IQR=___________mg/dL   e) Above what value are the highest​ 15% of​ adults' cholesterol​ levels?   ___________​mg/dL

In the 1980's it was believed that congenital abnormalities affected about 5.4% of the nation's children. Some people believe that an increase in the chemicals in the environment has led to an increase in the number of abnormalities. A recent study examined 400 randomly selected children and found that 29 of them showed signs of an abnormality. Does this provide evidence that the risk of congenital abnormalities has increase? Use a 0.05 to make your decision. What is the resulting test statistics?

A study was undertaken to see how accurate food labeling for calories on food that is considered reduced calorie. The group measured the amount of calories for each item of food and then found the percent difference between the measured and labeled amount of calories. The group also looked at food that was nationally advertised, regionally distributed, or locally prepared. Do the data indicate that at least one of the mean percent differences between the three groups is different from the others? The data summarized in the table below. National 3.15 Regional 36.75 Local Mean Standard Deviation Source Between Within 151 Total Fill in the hypotheses below: Ho: All the means are equal. Ha: At least one mean is different from the others. 7.4359 14.1558 SS 70.0204 Part 2 of 3 Complete the following ANOVA summary table (a 0.10). Round your answers to three decimal places, if necessary, and round any interim calculations to four decimal places. Sample Size df 20 12 8 MS - F P-value

According to the U.S. Census, the average adult woman is the United States is 65 inches tall and the standard deviation is 3 inches.  If Zsike is 67 inches tall, what is her z-score?