Question

CONFIDENCE INTERVAL PROJECT – Day 3

AFTER YOUR DONE CALCULATING, FOR EACH CONFIDENCE INTERVAL:

Describe your process of constructing the 95% CI

Interpret your results of the CI in context

Do you believe your CI is accurate? Explain why or why not, using values as your justification. (You will not be graded on whether or not it’s accurate, but instead on how you discuss its accuracy.)

Who do you think might be interested in your data? Why? How might they use it?

On this sheet, you will be calculating 95% Confidence Intervals for your data. Fill in all of the values for each piece, the formula, then show the full calculation for the CI. Write the CI in 2 different ways:

• In + notation

• In interval notation: ( ________ , ________ )

• When you record standard deviation- round to the nearest tenth.

Use the back of this sheet if extra space is needed.

PROPORTION CONFIDENCE INTERVAL:

p-hat = 11/30=.37

n = 30

z* =

Formula used:

Calculations:

95% Confidence Interval in both forms:

MEAN CONFIDENCE INTERVAL

x-bar =

s =

n =

z* =

Formula used:

Calculations:

95% Confidence Interval in both forms:

DATA TO USE TO ANSWER THOSE QUESTIONS:

Write out your question exactly as you will ask it to your sample. For example, “Do you have red hair, YES or NO?” Your question will most likely be a YES/NO question.

Question: Do you play fortnite?

Ask your question to at least 30 people. Be creative with this! You can set up a Facebook poll, Instagram poll, text friends, call friends, ask family/roommates, etc. Record their responses here as tallies:

          5 5 1

Yes: IIIII IIIII I

No: IIIII IIIII IIIII IIII

          5 5 5 4

Calculate the proportion of people who answered YES. Show your work below:

11/30 = 37%

What symbol would you use to represent that value? p Is it a statistic or parameter?

(Circle one) PARAMETER

MEAN CONFIDENCE INTERVAL

Write out your question exactly as you will ask it to your sample. For example, “How much do you weigh?”

Question: How many times a day on average do you play fortnite?

Ask your question to at least 30 people and record your results here.

0, 5, 2, 0 , 3 ,

1, 0 , 0, 7, 2,

0, 2, 0 , 0, 0,

4, 3, 0, 5, 2,

6, 0, 0, 2, 3,

0, 6, 2, 0 , 4

Calculate the average of your sample. Show your work below:

59/30= 1.96

Answer 1

S.E Means Standard Error.

z alpha value will be extracted from standard normal area tabulated values.