The Probability of Madness
1.27 Joey’s first 14 quiz grades in a marketing period were
86 84 91 75 78 80 74 87 76 96 82 90 98
(a) Use the formula to calculate the mean. Check using “1-Var Stats” on
your calculator
Wow that’s an easy one. I hope
she doesn’t want me to show my work, I hate when math teachers make me do that
for the simplest problems. Where’d my calculator go? I swear I had it like five
seconds ago. Oh, there it is.
A) 85.
(b) Suppose Joey has an unexcused absence for the 15th quiz,
and he receives a score of zero. Determine his final quiz average. What
property of the mean does this situation illustrate? Write a sentence about the
effect of the zero on Joey’s quiz average that mentions this property.
Why can’t I just write down the
answer? What’s with all this complete sentence crap? It’s statistics not
English. I miss pre calc. Ms. Nastri never made me write complete sentences.
B) 79, this illustrates that the
mean is not resistant to outliers. The zero is an outlier, and lowers Joey’s
quiz average by 6 percent.
c) What kind of plot would best show Joey’s distribution of grades?
Assume an eight-point grading scale (A: 93 to 100; B: 85 to 92; etc.). Make an
appropriate plot, and be prepared to justify your choice.
What if I don’t want to justify
my answer? Can’t you just take my word for it? This isn’t my only class you
know. C) A stem and leaf plot, because it’s a medium amount of data, it will
put the data in order, and allow me to access the original data from the plot.
7 4,5,6,8
8 0,2,4,6,7
9 0,1,3,6,8
2
problems and half an hour later…
1.30 Last year a small accounting firm paid each of its five clerks
$22,000, two junior accountants $50,000 each, and the firm’s owner $270,000.
What is the mean salary paid at this firm? How many of the employees earn less
than the mean? What is the median salary? Write a sentence to describe how an
unethical recruiter could use statistics to mislead prospective employees.
I’m hungry. But I don’t have time
to cook. Screw you stats homework!! Ooooo popsicles! I thought I talked to my
dad about keeping junk food in the house. I’m trying to be healthy. Whatever,
popsicle for dinner I guess… God, I’m weak.
Mean= 60,000, 7 employees earn
less than the mean. An unethical recruiter could present the mean to make
people think that they would receive more money than they actually would,
because the mean is greatly affected by an outlier (270,000)
Two
problems and 1 hour later…
1.40 Which measure of center and spread should be used for the
following blah blah blah blah blah blah blah?
I think this work is actually
making me dumber! I CAN FEEL MY IQ PLUNGING.
Two
problems and an eternity later…
1.54 The mean and standard deviation measure center and spread but are
not a complete description of a distribution. Data sets with different shapes
can have the same mean and standard deviation. To demonstrate this fact, use
your calculator to find the mean and standard deviation for the following two
sets of data. Then make a stemplot of each and comment on the shape of each
distribution.
The quantity of remaining
homework > the amount of time left in the day. I JU-UST WANNNA TAKE A
NA-AP!!!!!!!!!!!!!!!!!!