Please read this tutorial in its entirety before you start working on the project

Deepak Kumar

Description

????Please read this tutorial in its entirety before you start working on the project. A. Inference for the mean of a single population: 1. Enter data in a column; Name the column appropriately. 2. Choose the appropriate method: 2.1. If the population standard deviation is available, the sampling distribution that we used was a standard normal (z-distribution). So, use the menu sequence Stat Basic Statistics 1-Sample z 2.2. Enter the column (by typing or double-clicking on the appropriate name in the left window of available columns) that contains data in the Samples in columns text box. 2.3. Enter the value of the known population s.d. in the standard deviation text box. Confidence Interval: 2.4. If you want to estimate the population mean with a confidence interval, choose Options. 2.5. Enter the desired confidence level, in the range 1 to 100, in the confidence level text box. 2.6. Make sure that the alternative text box says not equal to. 2.7. Click ok twice. 2.8. Interpret Hypotheses Test: 2.4. If you want to perform hypotheses test, check the Perform Hypothesis Test box. 2.5. Enter the value of the mean under null hypothesis in the Hypothesized mean text box. 2.6. Choose Options 2.7. Leave confidence level text box.to its default value. 2.8. Choose the appropriate alternative from the alternative drop-down menu. 2.9. Click ok twice. You will get the sample information – size, mean, and sample s.d., standard deviation of the ...

Informations

• Publié par: Arne
• Nombre de lectures: 10
• Langue: English

Extrait

Please read this tutorial in its entirety before you start working on the project.

A. Inference for the mean of a single population:

1.

Enter data in a column; Name the column appropriately.

2.

Choose the appropriate method:

2.1.

If the population standard deviation is available, the sampling distribution that we used was a

standard normal (z-distribution).

So, use the menu sequence

Stat

Æ

Basic Statistics

Æ

1-Sample z

2.2.

Enter the column (by typing or double-clicking on the appropriate name in the left window of

available columns) that contains data in the

Samples in columns

text box.

2.3.

Enter the value of the

known population s.d.

in the

standard deviation

text box.

Confidence Interval:

2.4.

If you want to estimate the population mean with a confidence interval, choose

Options

.

2.5.

Enter the desired confidence level, in the range 1 to 100, in the

confidence level

text box.

2.6.

Make sure that the

alternative

text box says

not equal to

.

2.7.

Click

ok

twice.

2.8.

Interpret

Hypotheses Test:

2.4

. If you want to perform hypotheses test, check the

Perform Hypothesis Test

box.

2.5.

Enter the value of the mean under null hypothesis in the

Hypothesized mean

text box.

2.6. Choose

Options

2.7. Leave

confidence level

text box.to its default value.

2.8. Choose the appropriate alternative from the

alternative

drop-down menu.

2.9. Click

ok

twice.

You will get the sample information – size, mean, and sample s.d., standard deviation of the sample

mean (standard error of the mean), confidence interval or bound, and computed value of the test statistic

and the P-value.

Use the P-value (and the LOS, if given) to write your conclusion.

3.

If the population standard deviation is not available, under appropriate assumption, the sampling

distribution that we used was a t-distribution. So, use the menu sequence

Stat

Æ

Basic Statistics

Æ

1-Sample t

Do as in #2, except that you don't know the population s.d., so you won't need step 2.3.

4.

When using the t-distribution the data is assumed to come from a normal population. So, you need to

verify this using the normal probability plot using the

normality test

and descriptive measures such as a

stem plot.

B: Inference for Proportions:

1.

Enter the data in one of two ways:

a.

Raw data: You have raw data -- which sample is a "success" (a value of 1) and which one is a

"failure" (a value of 0).

You enter the corresponding 1 or 0 in a column. Label this column

appropriately.

b.

You are given summarized data, for e.g., 5 defective parts in a sample 378 parts.

If you have raw data in one column:

2.

Use the menu sequence

Stat

Æ

Basic Statistics

Æ

1 Proportion

3.

Enter or insert the column that contains data in the

Sample in Columns

text box

4.

Follow the above steps (2.4-2.8 or 2.4-2.9) that you did for inference for mean.

If you have summarized data:

2.

Choose the

summarized data

radio button

3.

Enter the number of "successes" in the

Number of events

text box

4.

Enter the sample size in the

Number of trials

text box.

5.

Follow the above steps (2.4-2.8 or 2.4-2.9) that you did for inference for mean.

C: Inference for two population means using Two-

independent

Samples:

There are three different ways in which we might have data:

(a)

The data for the two samples are entered in different columns (Label the columns appropriately)

(b)

The data for the two samples are stacked in one column (Label the column appropriately and perhaps

you create another column to identify which data belongs to which sample. The second column is

called the

codes or also subscripts

.)

(c)

We are given the summarized data – mean of the first sample is… , s.d., of the first sample is .., etc.

1.

Use the menu sequence

Stat

Æ

Basic Statistics

Æ

2-Sample t.

(a)

If the data is in two separate columns,

a.

choose the radio button

Samples in different columns

b.

Enter the columns that contain Sample1 and Sample 2.

(b)

If the data is stacked in a single column with the subscripts (codes) in a separate column

a.

choose the radio button

Samples in one column

b.

Enter the column that contains the stacked data in

Samples

text box

c.

Enter the column that contains the identifying subscript (code) in

Subscripts

text box.

(c)

If the data is given in summarized form,

a.

choose the radio button

Summarized data

b.

enter information for the two samples in the boxes.

2.

Check the box

Assume equal variances

3.

Choose

Options

4.

Enter the value of the difference between the population means under the null hypothesis.

5.

Enter the desired

confidence level

if you want a confidence interval. Otherwise, leave it at the

default value.

6.

Choose the appropriate type of test from the

alternative

pull-down menu.

7.

Click

OK

twice.

Write your conclusion using the P-value

(and the LOS, if given.)

Remember to test your assumptions of normal populations using normality test and equal population

variances using box plots.

D: Inference for two population means using paired

samples:

1.

If the data on the two (dependent) samples are in two columns (appropriately named), then\

a.

Use the menu sequence

Stat

Æ

Basic Statistics

Æ

Paired-t.

b.

Choose the radio button

Samples in columns

c.

Enter(insert) the columns that contain sample 1 and 2 in the respective boxes

2.

If only the summarized data is given :

a.

Enter the sample size

b.

mean of the sample differences

c.

s.d. of the sample differences

3, Choose

Options

a.

Enter the confidence level

b.

Enter the value of the average, population difference under null hypothesis in the

Test

Mean

box

c.

Choose appropriate

alternative.

Click

OK

twice.

You could also use Minitab in a similar manner to compare two population proportions and do

inference on population variance(s).