1. The figure below depicts six curves:
    s21q05.gif (3004 bytes)
    Which, if any, of the curves in the figure above look(s) like a normal curve? If the curve is a NOT normal curve, tell why.
  2. The diagram below depicts three normal curves
    Three normal curves with different means and standard deviations

    1. _______ Which curve has the smallest mean?
    2. _______ Which curve has the smallest standard deviation?
    3. _______ What is the mean for curve A?
    4. _______ What is the apparent mean for curve B?
  3. Normal curve diagramI jog from the College to Kolonia in a mean time = 61 minutes with a standard deviation s = 7 minutes. My times are normally distributed about the mean.
    1. _______ What is the probability that a run will take less than 61 minutes?
    2. _______ What is the probability that a run will take more than 68 minutes?
    3. _______ If I run 50 runs home during 2001, how many runs would be expected to last between 54 minutes and 68 minutes?
  4. Use = 61 and s = 7 to convert x = 51 minutes to a z value.
Statistic or Parameter Symbol Equations Excel
Normal Statistics
Calculate a z value from an x z = standardize.gif (905 bytes) =STANDARDIZE(x, , s)
Calculate an x value from a z x = s z + =s*z+
Calculate a z-statistic from an x z xbartoz.gif (1022 bytes) =(x - )/(sx/SQRT(n))