Stats. 2510
March 2, 2017
Chpt. 8
Section 8.2
Confidence intervals for One Population Mean when sigma is known
*looking for mu
Confidence intervalsrequires three pieces of info.
1. Confidence level (95%, 90%, etc.)
2. Point Estimate (usually x bar)
3. Mar
Bethany Burgess
Obesity In America
Pie graphs should be diagrammed using percentage form so that the represented information adds up to
100% (or the completed circle). This doesnt account for the entire world population. Therefore a pie
graph is inappropr
Stats. 2510
Feb. 9, 2017
Chpt. 5
Section 5.2
Mean and Standard Deviation of Discrete Random Variables
Mean of D.R.V X is denoted by (mu)
= x p ( X =x)
Expected value is frequently used in place of the term mean
Interpretation of Mean of Random Variable
La
Stats. 2510
Chpt. 6
Section 6.1
Normally Distributed Variable
Basic Properties of Density Curves
Property 1 always on or above horizontal axis
Property 2 total area under density curve and above horizontal
Density Curve graph of continuous probability dis
Stats. 2510
1/24/17
Chpt. 3 Section 3.1-3.3
Section 3.1
Measures of Center
Descriptive Measures
Two Types of Descriptive Measures
1. Measures of Centerlooking at different ways to describe what a typical value is of data set
2. Measures of Variationspread
Stats. 2510
Jan. 26, 2017
Section 3.4-3.5
3.4: Five Number Summary; Boxplots
Percentilesfor each percentage (p) between 0 and 100, the pth divides the bottom p% from top (100-p)
%
Ex: 30th percentile: P30=30% below and 70% above
Quartilesdivide a data set
Stats. 2510
February 7, 2017
Chpt. 4
Section 4.3
Rules of Probability
1. Probability Notation
E is event, then P(E) represents probability of E occurring
F/N number of ways event can occur
2. Special Addition Rule (must be exclusive events)
A and B are mu
Stats 2510
Section 2.3-2.4
Organizing Quantitative Data
For quantitative you will need frequency or relative frequency distribution
Observations (1 individual measurement) grouped into classes or categories
*Rule of thumb-5-20 class; no more than 20
Class
Statistics
Chpt. 2
Section 2.1
Variables and Data
Variablescharacteristic that varies from one person or thing to another
Qualitative variable numerically valued variable (categorial)
Exampleseye color, gender, blood type, and zip code
Quantitative variab
Stats. 2510
Chpt. 1
Sec. 1.1
Statisticsscience or practice of the collection, analysis, and interpretation of data
Descriptive Stats methods for organizing and summarizing info.
Examplebaseball stats
Organizing Summary ChartsConstruction of graphs, charts
Lecture 1:
SCIENTIFIC METHOD constitute data (example- movie ratings) STATISTICS: a
science of drawing conclusions from data (EXAMPLE- mean=3.3/4 stars) CATIGORICAL
VARIABLES: Social Class, Political Party, Population density, religion QUANTITATIVE VARIAB
Lecture 5: DESCRIPTIVE STATS organizes and summarizes the available data in a
meaningful way (You know everything about the data). Statistical tools/procedures to help
organize, summarize, and simplify a large set of data. INFERENTIAL STATS infers populat
Lecture 10: Distribution of Sample Means-is the collection of sample means for all the possible random samples of a particular size that can
be obtained from a population. The distribution of sample means is a population distribution. Central Limit Theor
Q1
Based on a sample of 50 x-values having mean 35.36 and standard deviation 4.26,
(a)
test at the 0.05 level of significance the null hypothesis : = 34 versus the alternative : 34.
(b)
find a 95% confidence interval for the population mean.
(c)
determine
Q1
A.
To find P(a < Z < b) = F(b) - F(a)
P(X < 0.03) = (0.03-0)/1
= 0.03/1 = 0.03
= P ( Z <0.03) From Standard Normal Table
= 0.51197
P(X < 1.01) = (1.01-0)/1
= 1.01/1 = 1.01
= P ( Z <1.01) From Standard Normal Table
= 0.84375
P(0.03 < X < 1.01) = 0.84375
East Brunswick High school has 1600 students. A sample of 160 students was selected to study
the average monthly income of students. Since sample size is greater than 30, how much error
would you expect in finding the average income of all students?
a) 5
Q1
A population has = 80 and = 12. Find the z statistic corresponding M = 84 for a sample if n = 5. MY ANSWER: I got z = .75. Is this correct?
Ans.
Test Used: Z-Test For Single Mean
Set Up Hypothesis
Null Hypothesis H0: U=80
Alternate Hypothesis H1: U!=80
Q1
Ans.
A.
i.
Mean = Sum of the observations / No.of the observations
Here n = 20 ; Sum of the observations = 127
Mean = 127/20 = 6.35
ii.
Median is the middle observation. If N is odd, use the formula (N+1)/2 th observation. If it is even use the formula
Q1
Explaining confidence. A student reads that a 95% confidence interval for the mean ideal weight given by adult American women is 140 1.4 pounds. Asked
to explain the meaning of this interval, the student says, 95% of all adult American women would say
When calculating the standard deviation and variance from a sample, which of the following is the
denominator for the biased estimate of the population standard deviation and the biased estimate
of the population variance? ( Point)
N
N1
N+1
N2
N+2
Answer)
Please show all work. Include formulas, calculations, or definitions necessary to solve the problems. I recommend that you use Excel. You may also use Word, but must attach the Excel
workbook used for calculations or paste the work in the document. Feel f
Q1
The conductivity of fibrous-glass board. How well materials conduct heat matters when designing houses, for example. Conductivity is measured
in terms of watts of heat power transmitted per square meter of surface per degree Celsius of temperature diff
Q1
Sixty percent of patients undergoing a certain hospital procedure are expected to require an overnight stay. The hospital schedules 8 patients for this
procedure each day. They set aside 6 beds to accommodate expected overnight stays for these patients
Data from Table Splitting for each year
Excelformulas
ForSum:
SUMIFS(B2:B2151,C2:C2151,"2002")
SUMIFS(B2:B2151,C2:C2151,"2003")
Likewise till SUMIFS(B2:B2151,C2:C2151,"2011")
ForCount :
COUNTIF($C$2:$C$2151,"2002")
COUNTIF($C$2:$C$2151,"2003")
Likewise t
Q1
Some insurance companies claim that the rate of serious and fatal accidents is higher when the car size is smaller, and therefore question the policy of
offering reduced rates to owners of small cars. To investigate this, a researcher analysed a sample
Q1
For the following set of data, find the range and the interquartile range. Label each answer
with the appropriate term. Scores: 3, 2, 6, 4, 5, 3, 1, 6
ANS
Range = Maximum Minimum
Maximum value in list = 6
Minimum value in list = 1
Range = Maximum Minim
Q1
1.) A radio station that plays classical music has a "by request" PROGRAM each Saturday evening. The percentages of requests for composers on a
particular night are as
follows.
Bach
19%
Beethoven
12%
Brahms
8%
Dvorak
3%
Mendelssohn
7%
Mozart
17%
Schube