A study to examine the effect of lighting type and assembly method on the productivity of workers on a production line for electronic circuit boards produced the following results: Lighting (B) Assembly Method (A) Fluorescent Inc andescent Means 42, 45 45, 32 1 49,32 37, 30 42 36 Means 37 41 39 Grand Mean NARREND a. What are the total degrees of freedom for this experiment? b. What is the computed value for Factor A (assembly method) sum of squares (SSA)?

8. An analyst is comparing data collected from randomly assigned test sub- jects who used two different types of hand cream (designated I and II), each for a period of six months. The subjects used one type of cream on one hand and the second on the other and reported a "softness" factor on a scale of 1 to 10 for each hand. What steps should the analyst take to determine which cream is more effective? (A) Calculate the mean difference between the right-hand results and the left-hand results, then carry out a one-sample z-test. (B) Calculate the difference in means between the right-hand results and the left-hand results, then carry out a two-sample z-test. (C) Calculate the mean difference between the right-hand results and the left-hand results, then carry out a one-sample t-test. (D) Calculate the difference in means between the right-hand results and the left-hand results, then carry out a two-sample t-test. (E) Calculate the individual differences between the Type I and Type II…

A college alumni Organization sent a survey to all recent graduates to ask their annual income. 20% of the alumni responded, and their mean annual income was $40,000  with a standard deviation of $10,000. Explain why these data should not be used to construct a confidence interval for the mean annual income of all recent graduates.

A factor in determining the usefulness of an examination as a measure of demonstrated ability is the amount of spread that occurs in the grades. If the spread or variation of examination scores is very small, it usually means that the examination was either too hard or too easy. However, if the variance of scores is moderately large, then there is a definite difference in scores between "better," "average," and "poorer" students. A group of attorneys in a Midwest state has been given the task of making up this year's bar examination for the state. The examination has 500 total possible points, and from the history of past examinations, it is known that a standard deviation of around 60 points is desirable. Of course, too large or too small a standard deviation is not good. The attorneys want to test their examination to see how good it is. A preliminary version of the examination (with slight modifications to protect the integrity of the real examination) is given to a random sample of…