Greg snow
47 snow
Exam 1
August 28, 2012
A systematic and objective method for measuring variation
Because of variation statistical conclusions about hypothesis are not accurate.
State question- articulate
Plan solutions- plan statistical analysis
So
Practice questions for Exam 3
1.
Fill in the blank: The t-distribution with 8 degrees of freedom has _ the
standard Normal distribution.
A. the same center but is more spread out than
B. the same center but is less spread out than
C. the same center and s
BYU Statistics 121 Formula Sheet
x
1
xi
n
x
s
Means
z
i
x
2
n 1
Observation < Q1 (1.5 x IQR)
Or
Observation > Q3 + (1.5 x IQR)
x 0
x z*
n
t
x 0
s
n
x t*
with df = n 1
t
n
z
x
x z
z *
n
m
2
s
n
with df = n 1
x1 x2
11
sp
n1 n2
x1 x2 t * s p
with df = n
Glossary for exam 3
: The symbol for level of significance (probability of making a type I error)
: The probability of failing to reject (accepting) a false null hypothesis (probability of making a type II
error)
Alternative hypothesis: The hypothesis tha
A
STATE:
Atthe=0.05level,istheresufficientevidencetoconcludethatthemeanweeklysalaryofall
seniorassemblylineworkersislessthan$500perweek?
PLAN:
1 one sample t test for mean
2 the mean of workers wages of all seniorassemblylineworkers
3Nullis500andthealter