52 cards what is the probability that a card drawn is a diamond

One card is dealt from a 52 card deck. find the probability that the dealt card is a 4 or a black 7

Find the midpoint m of z1=(8+5i) and z2=(12+3i)

17. a researcher measures three variables, x, y, and z for each individual in a sample of n = 20. the pearson correlations for this sample are rxy = 0.6, rxz = 0.4, and ryz = 0.7. a. find the partial correlation between x and y, holding z constant. b. find the partial correlation between x and z, holding y constant. (hint: simply switch the labels for the variables y and z to correspond with the labels in the equation.) gravetter, frederick j. statistics for the behavioral sciences (p. 526). cengage learning. kindle edition.