The blood platelet counts of a group of women have a bell-shaped distribution with a mean of 250.8 and a standard deviation of 65.5.
(All units are 1000 cells/μL.)
Using the empirical rule, find each approximate percentage below.
a. What is the approximate percentage of women with platelet counts within 1
of the mean, or between 185.3
b. What is the approximate percentage of women with platelet counts between 54.3
Researchers measured the data speeds for a particular smartphone carrier at 50 airports. The highest speed measured was 72.7
Mbps. The complete list of 50 data speeds has a mean of x=16.65
Mbps and a standard deviation of s=34.84
a. What is the difference between carrier’s highest data speed and the mean of all 50 data speeds?
b. How many standard deviations is that [the difference found in part (a)]?
c. Convert the carrier’s highest data speed to a z score.
d. If we consider data speeds that convert to z scores between −2
and 2 to be neither significantly low nor significantly high, is the carrier’s highest data speed significant?
Use z scores to compare the given values.
Based on sample data, newborn males have weights with a mean of 3227.7g and a standard deviation of 581.8 g. Newborn females have weights with a mean of 3007.4 g and a standard deviation of 578.4 g. Who has the weight that is more extreme relative to the group from which they came: a male who weighs 1700 g or a female who weighs 1700 g?
Since the z score for the male is z=
and the z score for the female is z=,
Use the following cell phone airport data speeds (Mbps) from a particular network. Find the percentile corresponding to the data speed 11.1