The inflation rate is calculated a. by determining the percentage change in the price index from the base year. b. by determining the change in the price index from the preceding period. c. by determining the percentage change in the price index from the preceding period. d. by determining the change in the price index from the base year.

Dr. dow jones wants to know whether a problem-based approach to teaching economics will result in higher academic performance than his traditional method. of the six sections of economics 101 at his university, dr. jones randomly assigns three sections to the traditional method and three sections to the problem-based method for unit 1 of the course. then all sections switch the instructional method for unit 2. he plans to compare the performance of the two groups of sections on their unit 1 and unit 2 exams. this study employs a design.

Reliability and validity reliability and validity are two important considerations that must be made with any type of data collection. reliability refers to the ability to consistently produce a given result. in the context of psychological research, this would mean that any instruments or tools used to collect data do so in consistent, reproducible ways. unfortunately, being consistent in measurement does not necessarily mean that you have measured something correctly. to illustrate this concept, consider a kitchen scale that would be used to measure the weight of cereal that you eat in the morning. if the scale is not properly calibrated, it may consistently under- or overestimate the amount of cereal that’s being measured. while the scale is highly reliable in producing consistent results (e.g., the same amount of cereal poured onto the scale produces the same reading each time), those results are incorrect. this is where validity comes into play. validity refers to the extent to which a given instrument or tool accurately measures what it’s supposed to measure. while any valid measure is by necessity reliable, the reverse is not necessarily true. researchers strive to use instruments that are both highly reliable and valid.

Jiffy printing shops does a lot of printing job for college students. the shop use an average of 25 cases of copy paper each day during the 312 days last year. the shop opens 6 days a week for 52 weeks each year and closes on sundays. each case of paper costs $35. it conducts a count of its paper inventory at the end of every quarter of the year. the table below shows the inventory counting records for last year. inventory end of quarter 1 700 cases end of quarter 2 1,050 cases end of quarter 3 920 cases end of quarter 4 800 cases 1. what's jiffy's cost of goods sold last year? 2. what's jiffy's average aggregate inventory value? 3. what's jiffy's inventory turnover last year? 4. what is the printing shop's weeks of supply last year?