A transcriber should italicize

Eileen's elegant earrings produces pairs of earrings for its mail order catalogue business. each pair is shipped in a separate box. she rents a small room for $150 a week in the downtown business district that serves as her factory. she can hire workers for $275 a week. there are no implicit costs. what is the marginal product of the second worker?

Bakery has bought 250 pounds of muffin dough. they want to make waffles or muffins in half-dozen packs out of it. half a dozen of muffins requires 1 lb of dough and a pack of waffles uses 3/4 lb of dough. it take bakers 6 minutes to make a half-dozen of waffles and 3 minutes to make a half-dozen of muffins. their profit will be $1.50 on each pack of waffles and $2.00 on each pack of muffins. how many of each should they make to maximize profit, if they have just 20 hours to do everything?

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.