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Hand in:
N.b.: "cf." is short for
"compare to" in reference speak. From Latin "confer."
ff. = and following. I.e. = "That is" (Latin "id est").
E.g. = "For example" (Latin "Exempli gratia") N.b.="nota bene", note
well.
Sec. 1.3,, pp.69ff.
Density Handout:
complete the tables by counting squares. (Look
for patterns, to stay entertained...)
p.70, 1.116, 117, 1.18 (uniform density. 116 and118
are using the first density on the handout )
1.19 (mean, median, mode)
A. Use Table A (back flyleaf, both sides,
or pp.. T-2&3, back of book) just like the Density handout.
The "z" and ".00" columns are the equivalents of "x" and "area to the
left of x". Confirm that the area for z less than 0 = .5, area less
than 1=.8413, area less than 2 =.9772, area less than -1 = .1587.
By appropriate subtractions, calculate the area between 0 and 1, the
area between -1 and 1, the area between 1 and 2, and the area above 1.
.Only the above: Postpone the rest..
Normal density p. 84ff. Always sketch
the curve, mark the area(s) you need.
p. 57, 1.101&2, test scores, Rule
1.120 (sketch) 1.122 (pregnancies, rule)
1.165 compare 2 curves (graph, p. 76)
1.112 (Women talk more?) Use
the Rule to give the limits containing 68, 95, and 99.7% of the
speakers, M & F; and use that to answer (b). (I.e. are these
data Normal?)
1.24 Use Normal
Density Curve Applet to find Quartiles in
Normal
p. 681.103 test score z-scores
1.132&1.33 (SAT/ACT, compare) Find the
z-scores. Also sketch both normal curves, labeling the
axes in points, at + 1 s.d. and mark all the
students' scores on them.
1.126 (forward), 1.128 (backward) (standard
normal table)
- - - - - - - - - - - -
The rest of these on separate
paper as part of Day 7: Do all of these using the Normal
Density Applet http://www.whfreeman.com/ips7e/ to get answers. Leave space to
do the calculations to get the answers from Table A. Always sketch the curve, mark the
area(s) you need.
B. Simple warmup: Non-standard normal, table problems:
X is normal with mean 3 and s.d. 2. Find:
The proportion with X<1.5. 1.5 < X <
4.5.
p. 63, 1.105 & 106 test scores, proportions
1.144 (osteoporosis) Also sketch both curves
on the same axis.
1.145 a, b (pregnancy) (c will be assigned
later)
p.77 1.176d (75's are Raw
scores. You could transform each to the N(100,20) distribution,
if you remembered your formulas from parts a and b, or (shorter) you
can find the percents asked for directly from the separate grades'
distributions. In each case you've found the percentile for
a grade of 75.)
C. A small difference in means may give a surprisingly
large proportional difference in tails:
a) Return to the data of 1.165, p. 75&6, and calculate what
proportion of Females score below 450 and what proportion of Males
score below 450. Answer this: The proportion of Males
scoring below 450 is ____ times the proportion of Females scoring
below 450.
b) Some of the difference in (a) may be because the Male
s.d. is larger, not just the difference in means. Recalculate the
proportion of Males who would score before 450 if their mean were still
565 but their s.d. 49 (= F s.d.) The proportion is now ______.
This assumes, of course, that the Normal model holds up
into the tails; always questionable.
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Read, discuss
p. 77 1.173 summary #s enough?
p. 69, 1.111, sketch densities.
.Postpone the rest.
p. 69, 1.109&10: Sketch Normal; shift
and stretch
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Optional
.Postpone these.
Normal density
1.121 Use Normal
Density Curve Applet to
check on the Rule
1.23 (horse preg's , rule)
1.127 (forward), 1.129 (backward) (standard normal
table, more practice)
1.130 & 131 (Wechsler WAIS, more practice)
Use Normal Density Curve Applet http://www.whfreeman.com/ips7e/
(or theapplet for ips6e, etc.) to
check on all your
Normal calculations! (The Applet goes by .02's, and the text by
.01's so the answers may differ slightly)
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