What effect will increasing the sample size have on the width of the confidence band around the estimated parameter?

The computed t-ratio from an independent t-test will always be positive. 

Is it possible to have a z-score of 1.0 and a percentile rank of 45?

A researcher compared the mean number of risk factors for male and female undergraduate students.  What statistical technique would be most appropriate for this situation?

Where would the ecological validity of a research study be stronger?

A researcher was interested in evaluating if there was a relationship between participants’ weight and their vertical jumping score measured in inches.  What statistic would you use?

Power can range from -1 to +1.

At what level of significance are type 1 errors more likely?

A researcher developed an intervention designed to increase the grip strength of adults 85 years or older.  The researcher randomly selected 16 older adults and used available body mass index (BMI) data, to create 8 matched pairs on BMI. Within each pair, the researcher randomly assigned 1 participant to the intervention and 1 to the control group. The strength training program was implemented for 10 weeks (1 training session/week).  Immediately following the intervention, all adults were tested for grip strength.  Higher scores represent greater grip strength. What effect will increasing the number of matched pairs (instead of 8 pairs having 80 pairs) have on statistical power?

Is it appropriate to calculate a median for ordinal data?