Compute sample statistic, Use Hypothesis testing to

Compute sample statistic

Assignment Help Basic Statistics

Reference no: EM1379384

A psychologist develops a new inventory to measure depression. The population of "normal" individuals has mean score on this test of µ = 55 with σ = 12. To determine whether the test is sensitive to detecting those individuals that are severely depressed, a random sample of patients who are described as depressed by a therapist is selected and given the test. Presumably, the higher the score on the inventory, the more depressed the patient is. The data are as follows: 59, 60, 60, 67, 65, 90, 89, 73, 74, 81, 71, 71, 83, 83, 88, 83, 84, 86, 85, 78, 79

Use Hypothesis testing to determine if the new inventory differentiates between the patients who are described as depressed? Use an α = .05

Step 1: State Hypothesis

The Null hypothesis

H₀: µ_{depression measure} = 55

a. State the null hypothesis in your own words

The Alternative hypothesis

H₁: µ_{depression measure} ≠ 55

b. State the alternative hypothesis in your own words

Step 2: Set Criteria

α = .05 with a two tails

1768_Compute Sample Statistic.png

c. Using the table in the book fill in the values for p and z critical

Step 3: Compute Sample Statistic

In this example we are not given M or n. We are however given the sample scores, so all we have to do to get M is to find the average of the scores. We get n by counting the frequency of scores n =21.

M = (59 + 60 + 60 + 67 + 65 + 90 + 89 + 73 + 74 + 81 + 71 + 71 + 83 + 83 + 88 + 83 + 84 + 86 + 85 + 78 + 79)/ 21 = 1609/21 = 76.62

σ_M = σ/√n σ_M = 12/√21 = 12/4.58 = 2.62

z = (M - μ)/ σ_M z_obt = (76.62 - 55)/ 2.62 = 21.62/ 2.62 = 8.25

d. Use Excel to replicate the test statistic that was computed by hand. Include the output or a copy of your excel file

Step 4: Make a decision

e. Did you reject the null/fail to reject the null

f. State your conclusions in your own words

2. A rocket scientist, Dr. Boom, is measuring the weight of a sample of 25 rockets in his latest spaceship. He thinks they might weight less than the average rocket. The sample has on average 102 lbs with a standard deviation of 10 lbs. The average rocket weights 106 lbs.

Use Hypothesis testing to determine if Dr. Boom is correct, that his sample of 25 rockets weight less than the average rocket. Use an α = .01

Step 1: State Hypothesis

The Null hypothesis

H₀: µ_rocket ≥ 106

a. State the null hypothesis in your own words

The Alternative hypothesis

H₁: µ_rocket< 106

b. State the alternative hypothesis in your own words

Step 2: Set Criteria

α = .01 with a one tailed test

df = n - 1 = 25 - 1 = 24

683_Compute Sample Statistic1.png

c. Using the table in the book fill in the values for p and t critical

Step 3: Compute Sample Statistic

d. In this example we are not given the raw data which means we cannot use Excel to compute the test statistic; however, we are given all the necessary values to compute the test statistic by hand. Compute the test statistic.

Step 4: Make a decision

e. Did you reject the null/fail to reject the null

f. State your conclusions in your own words

Reference no: EM1379384

Questions Cloud

Clock drift results in error : Think about a frame being sent using synchronous transmission. Suppose that samples are taken at the middle of the bit period and that the clocks are synchronized at the starting of each frame.

As part of your development as a new member of ikea''s retail : As part of your development as a new member of IKEA's Retail Division you have been exciting by Andres Moberg to with identifying key strategic issues facing the company

How would you classically condition an adventure : How would you classically condition an adventuresome 2-year-old to be more fearful of running across a busy street near her house.

How does cognitive functioning enhance diversity : Is perceptual learning necessary for correct interpretation of pictures? If so, which aspects of picture perception are most affected by learning also experience.

Compute sample statistic : Use Hypothesis testing to determine if Dr. Boom is correct, that his sample of 25 rockets weight less than the average rocket.

What is method by which researchers conduct research : There are three different methods to researching sociology: positivist, interpretive also critical. What is method by which researchers conduct research with personal neutrality also are value-free.

Explain what is net trade credit and how is it computed : Explain what is net trade credit? How is it computed? Why is it important? Explain what is a compensating balance? Why are they used? How can they be a advantage for the company borrowing money?

Single table manipulation and table join manipulation : Explain one drawbacks and benefits of Internet enabled technology use by firms to augment information flow both within and between company departments, partners, and consumers?

How did pavlov also watson focus on scientific inquiry : How did Pavlov also Watson focus on scientific inquiry of behaviours differ from earlier viewpoints of structural lists, psychoanalysts also functionalities.

User Account

All Pages