STA2023
Extra Credit #2
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Chapter 7
#53 parts c,d, and g
Part c) We usually, interpret r after we change it to R2. So
R 2 (0.685) 2 0.4692
So 46.92% of the variation in Math SAT scores is accounted by the Verbal scores.
Part d
Chapter 8 #39
Part a) Stronger if humans were removed.
Part b) Yes, humans may live longer due to modern medicine and our common knowledge of things. So perhaps humans should not
be considered in this
Chapter 7
#65 part b
Part b) In exercise #63, you were asked to find the equation to predict Calories from Fat. So you let Fat be the
explanatory (x) and you let Calories be the response (y). Here we
Ch.5 #41
a)
If these values were Normally distributed (bell-shaped curve), we would expect about 2.5% of receivers to gain more
yards than 2 standard deviations above the mean. This is because within
STA2023 Extra Credit #3 (chapters 15-19)
Part I (Focusing on Chapter 15)
SOLUTIONS
Solution: 1.
Suppose 14% of people are left handed. What is the probability that a random sample of 200
people will h
Ch.5 #43 part c
c)
N(1152, 84)
40%
x1 1152 x2
So we need to find the values that cutoff the middle 40%. I have labeled them as x1 and x2.
We need to figure out what percentiles these values represent.
Ch.5 #45 part c
c) The IQR = Q3 Q1. So we need to find the values for Q1 (25th percentile) and Q3 (75th percentile).
N(1152, 84)
25%
Q1
1152
N(1152, 84)
75%
1152
Q3
To find percentiles you could use t
Chapter 8
#33 part e
Part e) So here they want the actual heating cost for the month in which the temperature averaged 10o.
From the graph above, we can see that the residual for this month is about -
Chapter 7 exercise #4
Recall the formula for a residual:
Residual = observed value predicted value
or
=
In this case, you could write it as =
= 5.94 + 0.1875
This problem refers back to the model
Chapter 5
The formula for z-scores is z x
xx
x
or if we are considering values for the entire population we use z x
.
s
We want the z-score for x=380. So z x
380 242.4
1.20
114.51
So the z-score i
Chapter 5
a) The distribution is not normal. If the distribution were normal, then in this Normal Probability plot we would see
the values (in red) follow roughly a diagonal straight line, with approx
Chapter 5
Part a) The distribution is skewed to the right. There are two ways we could determine this.
1. The mean is larger than the median, which indicates that the data are skewed to the right.
2.
Ch.5 #15
In this problem, you are given some statistics for ACT scores from the data taken from 2355 ACT scores.
Lowest score = 19
Mean = 27
Standard deviation = 3
Q3 = 30
Median = 28
IQR = 6
They tel
Chapter 3 #8 help
Since standard deviation is a measure of spread (actually, very close to being the average distance each
value is from the mean) that takes into account ALL the values (just consider
Ch.5 #21
Stats Exam Scores:
First Test:
Mean = 65
Standard deviation = 10
Second Test:
Mean= 80
Standard deviation 5
Derricks Scores:
Test 1 = 80
Test 2 = 80
Julies Scores:
Test 1 = 70
Test 2 = 90
Bot
Ch.5 #35
a)
(sorry so sloppy)
N(10.4, 4.6)
-3.4 1.2 5.8 10.4 15 19.6 24.2
b) Because the distribution is normal, from the 68-95-99.7 Rule, we expect approximately 95% of trees to fall within 2 standar
Chapter 3 #17 part a)
Part a)
In the description, we are given that there are a total of 36 vineyards.
The vertical axis of the histogram gives the number (frequency) of vineyards in each size range.
Module I: INTRO & FEDERALISM
Know the material & issues below from chapter 2
Know the relationship between state law, state constitutions, & the federal constitution.
Describe the key features that st
Chapter 14 #37 part a
Part a)
There are 10 batteries.
3 are dead, so 7 are good
You choose 2 at random
X = #of good ones you get
Since you are only picking 2 batteries, the # of good ones you could po
HW 15A
These problems are due Thurs. 3/10 at 11:59pm. These graphs must be drawn by hand on a piece
of paper. They should be draw neatly and clearly numbered. Make sure that you label the axes
and put
STA 2023 - Exam 3 Review
Use the following information for the next 3 questions
A controversy that Americans have debated in recent years is the issue of gay marriage. In a random sample of 180 Americ
Exam 2 Review for STA 2023
How to review for the test:
1. Study your notes.
2. Go over the I can statements and recognize what your strengths and weaknesses are.
3. St
Exam 1 Review for STA 2023
How to review for the test:
1. Study your notes.
2. Go over the I can statements and recognize what your strengths and weaknesses are.
3. St
Calculator Instructions for Chapter 20:
You will NOT be required to find the degrees of freedom for the difference between two
means (for confidence intervals or hypothe
Calculator Instructions for Chapter 5:
To use normalcdf on your calculator:
This will help you find the percentage of data points below, above, or between certain values.
Hit:
1. 2nd
2. VARS for DISTR
Deanna Henriksen
STA 2023
Name:_
STA 2023 Project 2
Be sure to show all your work for full credit. NO WORK, NO CREDIT. Due by 6pm on Friday, June 17th. Round
all final answers to two decimal places un