Individual assignment – time to practice parts

For the following research questions, create one null hypothesis, one directional research hypothesis, and one nondirectional research hypothesis.

What are the effects of attention on out-of-seat classroom behavior?

Null hypothesis- their will be no effect on attention

Non-directional hypothesis- their will be an effect on attention

Directional- their will a greater difference in effects of out-of-seat classroom

What is the relationship between the quality of a marriage and the quality of the spouses’ relationships with their siblings?

Null hypothesis- there is no relationship of both

Non direction- there is a relationship of both

Directional- there is a less relationship of both

What is the best way to treat an eating disorder?

Null hypothesis- there is no better way of treating a disorder

Non-directional- there is a way of treating a disorder

Directional- there is a better way of treating a disorder.

Provide one research hypothesis and an equation for each of the following topics:

The amount of money spent on food among undergraduate students and undergraduate student-athletes

Research hypothesis is: amount spent is greater $1000

Ha. Amount spent is > 1000

The average amount of time taken by white and brown rats to get out of a maze

Research hypothesis is: amount spent is less than 1 hr

Ha. Amount spent is < 1hr

The effects of Drug A and Drug B on a disease

Research hypothesis is: there are great effects by these drugs on the disease

Ha. Effects of drugs are > 1

The time to complete a task in Method 1 and Method 2

Research hypothesis is: time taken is less than 20 minute

Ha. Time taken is < 20 min

Why does the null hypothesis presume no relationship between variables?

The null hypothesis presumes no difference since it assumed to be no difference between variables unless tested and proofed to be wrong. That is the reason why it is called null.

Create a research hypothesis tested using a one-tailed test and a research hypothesis tested using a two-tailed test.

What does the critical value represent?

  • One-tailed test
  • Ho: Population Average = 30
    Ha: Population Average >30
  • Two-tailed test
  • Ho: Population Average = 20 (this is the hypothesis of no difference)
    Ha: Population Mean =/= 20

Given the following information, would your decision be to reject or fail to reject the null hypothesis? Setting the level of significance at .05 for decision making, provide an explanation for your conclusion.

  • It is that value of test statistic that must be exceeded for the null hypothesis to be rejected.

The null hypothesis that there is no relationship between the type of music a person listens to and his crime rate (p < .05).

When the p-value obtained from the test statistic is less than 0.05 the then the null hypothesis that there is no relationship between the types of music a person listens to and his crime rate becomes true. But if p value is > 0.05 then null hypothesis is rejected.

The null hypothesis that there is no relationship between the amount of coffee consumption and GPA (p = .62).

If the test statistic obtained is equal to 62 then the null hypothesis is accepted as with no significant difference. If the p-value is not equal to 62, then i will reject the null hypothesis.

The null hypothesis that there is a negative relationship between the number of hours worked and level of job satisfaction (p = .51).

If the test statistic obtained is equal to 51 then the null hypothesis is accepted as with no significant difference. If the p-value is not equal to 51, then i will reject the null hypothesis.

Why is it harder to find a significant outcome (all other things being equal) when the research hypothesis is being tested at the .01 rather than the .05 level of significance?

Testing is a statistical inference of ‘contradictory’ data to reject a null hypothesis. When Test conducted at 0.01, research hypothesis involves a much smaller set of values. When Test conducted at 0.05, research hypothesis involves a quite large set of data. Hence, the reason for more instances of using 0.05 level of significance.

Why should we think in terms of “failing to reject” the null rather than just accepting it?

When is it appropriate to use the one-sample z test?

  • It is usually good to disapprove the null hypothesis by carrying out research. This research will provide important information about the data through observation.

it is appropriate to use z-test mainly when the population standard deviation is known and when the data is drawn randomly from the population.

What similarity does a z test have to a simple z or standard score?

Just like the z test makes into use raw data values as also standard score.

For the following situations, write out a research hypothesis:

Bob wants to know if the weight loss for his group on the chocolate-only diet is representative of weight loss in a large population of middle-aged men.

HO: Their no significant difference by taking chocolate-only diet.

Ha: there is significant difference in the loss weight by use of chocolate-diet

The health department is charged with finding out if the rate of flu per thousand citizens for this past flu season is comparable to the average rate of the past 50 seasons.

HO: Their no significant difference between the rates of flu

Ha: There is significant difference between this years’ flu rate and the last 50 seasons

Blair is almost sure that his monthly costs for the past year are not representative of his average monthly costs over the past 20 years.

HO: Costs of the past year are representative of the past year.

Ha: there is significant difference in costs and average monthly costs and monthly costs over the past 20 years.

Part B

Complete the following questions. Be specific and provide examples when relevant.

Cite any sources consistent with APA guidelines.

Answer
The average raw math achievement score for third graders at a Smith elementary school is 137; third graders statewide score an average of 124 with a standard deviation of 7. Are the Smith third graders better at math than third graders throughout the state? Perform the correct statistical test, applying the eight steps of the hypothesis testing process as demonstrated on pp. 185–187 of Statistics for People Who (Think they) Hate Statistics. Step 1. Ho: smith third graders are better than others. Ha: smith graders are not different from the others.Step 2. We define our alpha to be 0.05 Hence we will reject the null if the test statistic is less than -1.96 or greater than 1.96Step 3. Calculate the z statistic to find the p value (137-124)/7/√2 = 2.62Hence the test statistic is greater than 1.96We reject the null hypothesisWe can therefore say that smith graders are not different from the others.
What is a research question that you would like to answer? Write the null and research hypotheses. Would you use a one- or two-tailed test? Why? Do age matters with body size.Ho: age don’t matter with body sizeHa: body size matters with ageI would use one tailed test because it give more comparison than two tailed tests
What do we mean when we say that a statistical result is significant? What is the difference between a statistically significant and a meaningful result? Why is statistical significance important? It means that the result gives much difference with the null hypothesis value.
Describe a Type I error for the previous study that compares third graders’ math achievement. Describe a Type II error for that study. Type I occurs when we would have rejected the null hypothesis while it was actually true that smith graders are different with othersType II error occurs when we would have rejected the research hypothesis that smith graders are not different with others