MTB > execute 'nw2-1-3.mtb'
MTB > # Bill Qualls
MTB > # NW - Stats II - Lab 1 - #3
MTB > # This is NW2-1-3.MTB
MTB >
MTB > # 3. Invoices at a particular depot have amounts which follow a normal di
> stribution
MTB > # with a mean invoice of $110.70 and a standard deviation of $7.85.
MTB >
MTB > # Recall standard normal has mean=0 and stdev=1.
MTB > # Since this is not a standard distribution, we need to specify mean and
> stdev.
MTB > # The cdf instuction gives the area to the left of x.
MTB > # To get the area to the right of x, subtract cdf from 1.
MTB > # To get the area between two x scores, subtract their cdfs.
MTB > # Asign a constant to a variable starting with k: k1, k2, k3, ...
MTB >
MTB >
MTB > # What percentage of invoices will be over $130.25?
MTB > # Must use the cdf command and the normal subcommand.
MTB > # Note the semicolon on the first line, indicating a subcommand
MTB > # will follow, and a period on the second indicating end.
MTB > # Reminder: for "over", subtract cdf from 1
MTB > cdf 130.25;
SUBC> normal 110.70 7.85.
130.2500 0.9936
MTB > let k1 = 1 - 0.9936
MTB > print k1
K1 0.00639999
MTB >
MTB >
MTB > # What percentage of invoices will be below $91.50?
MTB > # Reminder: for "below", no other calculation is needed.
MTB > cdf 91.50;
SUBC> normal 110.70 7.85.
91.5000 0.0072
MTB > print k1
K1 0.00639999
MTB >
MTB >
MTB > # What percentage of invoices will be between $87.25 and $118.30?
MTB > # Reminder: for "between", subtract low cdf from high cdf.
MTB > cdf 87.25;
SUBC> normal 110.80 7.85.
87.2500 0.0013
MTB > cdf 118.30;
SUBC> normal 110.80 7.85.
118.3000 0.8303
MTB > let k1 = 0.8303 - 0.0013
MTB > print k1
K1 0.829000
MTB >
MTB > stop
*** Minitab Release 8.21 *** Minitab, Inc. ***
Storage available 16174