Unit 5 Quiz 2

General Formula

point estimate ± margin of error

Specific Formula for one sample

p-hat ± Z* sqrt((p-hat (1-p-hat))/n)

1.282

80% Confidence Z*

1.645

90% Confidence Z*

1.96

95% Confidence Z*

2.576

99% Confidence Z*

Margin of Error

sqrt[(p(1-p)/n]

Classify

Variable

Type of Study

Choose

Procedure

Parameter

Confidence Level

Check

Random (+independent for difference)

10%

Large Counts Condition

Calculate

Plug in Numbers

Calculate

Conclude

“We are _% confident that the true proportion that the interval ____ to ____ captures the true proportion of _____”

Specific Formula for two samples

(p-hat1 - p-hat2) ± z* sqrt[(p-hat1(1-p-hat1)/ n1) + (p-hat2(1-p-hat2)/n2)]

(+,+)

Convincing evidence the first proportion is greater

(-,-)

Convincing evidence the first proportion is smaller

(-,+)

No convincing evidence of a difference

Procedure

One sample z-interval for p

Two sample z-interval for p1-p2

Parameter

p= the true proportion of [context]

p1-p2= the true difference in proportion of [context] (p1 in context- p2 in context)

Confidence Level

Given in the problem

Random

Random Sample of ___ [in context]

Participants were randomly assigned

Independent Random Samples were taken

10% condition

Samples are less than 10% of entire population

OR
10% is not needed when you are not sampling without replacement

Large Counts Condition

Sample(p) >= 10

Sample(1-p) >= 10

Variables

State the variable and if it is categorical or quantitative for observational studies

If experiment: state explanatory and response variable