Question

Confidence Interval

Parameter: What is the true percentage of all my Facebook Friends who have 3+ tattoos?

Statistic: In a sample statistic of 324 Facebook Friends, 162 of them picked 3+ tattoos. This means my statistic, or sample percentage (­­­­p) was 50%

Margin of Error: zp(1-p)n=

Z=

p (p-hat) =

n =

Confidence Interval:

(My guess was 40%)

Hypothesis Test

Parameter and Hypothesis: What is the true percentage of all my friends who would identify having 3+ tattoos? Hypothesis (po) = 40%

Test Value: z=p-popo(1-po)n

po=

p (p-hat) =

n =

P-Value:

Decision Rule:

Answer 1

Solution-:

Let, X= Number of Facebook Friends who have 3+ tattoos among the 324

Given:

Sample percentage

Where, (From Z-table)

The 95% C.I. is

The required C.I. is  

Given:

Hypothesis:

Vs

The test statistic is given by,

At

  (From Z-table)

Decision rule: hence, fail to reject .