(Note the use of the vertical bar symbol to signify'given that').The overall probability that theFirst marble was BlueANDthe Second marble is Bluecan thenbe calculated as follows, using the multiplicative rule for combining conditional probabilities:P(First marble was BlueANDSecond marble is Blue)= P(First marble is Blue) XP(Second marble is Blue| First marble was Blue)= 0.3333 X 0.2857= 0.0952.Question 14The z score corresponding to a raw score represents the number of - - - - - that the raw scorediffers from the mean of the raw score distribution.1.points2.standard deviations3.percentiles4.variances➔Answer:Option2is correct.The z-scores are equivalent to standard deviations on the standard normal distribution, andeach unit on the z-scale represent one standard deviation of the raw score. (See section 2.3.3in the Guide for PYC3704).This implies that z=1 is equivalent to one standard deviation of xremoved from the raw score mean (μ for a population or x¯ for a sample) and zQuestion 15A test statistic is defined as - - - - -1.The quantity that is calculated to test a statistical hypothesis, by making use of thesample statistics.2.The quantity that is calculated to test a statistical hypothesis, by making use of thepopulation statistics.3.A descriptive statistic that describes an aspect of the sample data.4.A parametric statistic that describes an aspect of the population data.➔Answer:The correct choice would be Option1.Option 1 is the only description that is true.The terms “test statistic” and statistic can easilybe confused. It is therefore imperative to have a clear understanding of the two terms.
