Aportfolio’s risk is not equal to the weighted average of the individual stocks’ standard deviations. when returns on stock a increase, returns on stock b also increase. in general, this would mean that stocks a and b are positively correlated. the risk in a portfolio will increase if more stocks that are negatively correlated with other stocks are added to the portfolio.

Sharon had some insider information about a corporate takeover. she unintentionally informed a friend, who immediately bought the stock in the target corporation. the takeover occurred and the friend made a substantial profit from buying and selling the stock. the friend told sharon about his stock dealings, and gave her a pearl necklace because she "made it all possible." the necklace was worth $10,000, but she already owned more jewelry than she desired.

You've arrived at the pecan shellers conference—your first networking opportunity. naturally, you're feeling nervous, but to avoid seeming insecure or uncertain, you've decided to a. speak a little louder than you would normally. b. talk on your cell phone as you walk around. c. hold an empowered image of yourself in your mind. d. square your shoulders before entering the room.

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.