Explore BrainMass
Share

# Student's t-Test

The Student’s t-Test is a statistical hypothesis test based on the t-distribution which assesses whether the means of two different groups are statistically different from each other. Thus, the Student’s t-Test can be used to determine if two different sets of data are similar or in fact very different. If the scaling term of the data is known, then normally the z-Test would be utilized to assess the differences; however, if the scaling term is not known, then the t-Test can be used instead. This phenomenon occurs because the t-distribution takes the shape of the normal distribution without standardizing the mean to 0 and the standard deviation to 1 with the scaling term.

In statistics, the Student’s t-Test can be used in a variety of ways as long as the data collected originates from two different sources. For example, the t-Test can be used to assess the differences between one sample and a population, two different samples from two different populations (where the variances are equal) and two samples from the same population (one before a particular treatment and one after it).

The actual test statistic for the t-distribution is very similar for the z-statistic and it is as follows:

t = (x- µo)/(s/(n^1/2))

Where,

X is the sample mean

µo is the population mean

s is the sample standard deviation

n is the sample size

Thus, understanding the very basics of the Student’s t-Test is critical for accurately assessing the differences between two data sets.

### Hypothesis Testing: Type A Personalities

Assume that the subject population for whom data are reported are all Type A personalities. The hypotheses being tested were 1) whether there was a difference in DBP risk as a function of increasing age, 2) whether there was a difference in DBP as function of gender, 3) Whether Type A men and women show the same pattern of DPB a

### Hypothesis Testing of Mean..

Suppose that you wish to compare the characteristics of tuberculosis meningitis in patients infected with HIV and those who are not infected. In particular, you would like to determine whether the two populations have the same mean age. A sample of 37 infected patients has mean age of 27.9 years and a standard deviation of 5.6 y

### Hypothesis Testing of Proportion.

A study of cats and dogs found that 25 of 50 cats and 37 of 60 dogs slept more than 10 hours per day. At the .05 level of significance, is there sufficient evidence to conclude that the proportion of dogs that sleep more than 10 hours per day is higher? What test score did you find? Two decimal places, please. 1. Please do

### Using t test, chi square test and Wilconxon rank sum test

2. A student is interested in whether students who study with music playing devote as much attention to their studies as do students who study under quiet conditions (he believes that studying under quiet conditions leads to better attention). He randomly assigns participants to either the music or no- music condition and has t

### Perform Hypothesis Testing Under T Distribution with Given Data

I'm working on a project that deals with the impact of age on helicopter pilots and want to see if that after age 40 accidents occur more frequently. I would like to use a T test to test this but an unsure how to go about doing it. I think the hypothesis would be: H1: Accidents occur more frequently above the age of 40. H0:

### Three experiments that would use one sample t test

Describe three experiments that would use the three different t-tests -One Sample -Correlated Samples -Independent Groups

### Group Differences T Test: Public Perception

Use the "Public Perceptions" dataset attached. The county government is interested in determining if there is a difference in perceptions based on people that have utilized the county services in the past year and those that have not. Please complete the following: One-sample T-Test: Conduct a T-Test to determine if there

### Independent Sample t test using SPSS's

• Independent-Samples t Test with SPSS In your research, you may find that you must compare the means of two samples related to one particular variable. For example, you may have population samples from two ethnic groups that you wish to compare against income level. In these cases, you will need to use an independent-samples

### 10 Hypothesis Testing MCQs

True or False: The probability of Type I error is referred to as the significance level of the test. True False A Type II error is defined as: rejecting a true null hypothesis. rejecting a false null hypothesis. failing to reject a true null hypothesis. f

### Effects of Diet and Weight Control

A study in The Journal of the American Medical Association describes the effects of diets on weight control. In the study, 311 women were randomly divided into four groups. The first group followed the Atkins diet, which is based on very low carbohydrate intake. The second group followed the LEARN (lifestyle, exercise, attitudes

### Independent and Dependent t test, effect size

Find examples in the research that utilize the independent and dependent t-tests that are used to answer a question. Find the t value and its associated p value. Determine and evaluate the effect size and comment on the impact of proposed difference. Ask yourself and comment on your level of satisfaction with the "practical" sig

### SPSS output

Review the SPSS output file (see attachment) which reports the results of the between-group (independent group) one-way ANOVA to see if the mean alcohol by volume (%) of the beer differs as a function of quality of the brand as rated by a beer expert (in 2012). Answer the following questions based on your observations of the SPS

### Hypotheses Used for Paired T-tests

First, explain in your own words (no direct quotes, please) when you might employ a paired t-Test. Secondly, describe in words the hypothesis that is used for a paired t-Test. Thirdly, describe what assumptions must be met to use this test. Finally, where in your course project data set might you employ a paired t-Test?

### Analysis of Interaction Effect in the Model

First, explain in your own words (no direct quotes, please) what it means when there is an interaction between two factors. Secondly, describe in words the hypothesis that enables us to test for the interaction between two factors. Thirdly, describe the method for testing that hypothesis. Next, explain how we interpret the situa

### T-Test and Estimated Normal distribution

Calculate and Display, using Excel, the following: 1. Draw the statistics as a histogram. Do they resemble the Normal Distribution? 2. Find the median, the average grade and the standard deviation of the two terms. 3. Calculate using the t-student distribution to find out if there is a significant difference among these two

### Calculating T-statistic and Coefficient of Correlation

a) Given the equation: (See attached), what is the calculated t-statistic and is it significant at the 5 percent level? (Hint: Apply 2 rules) b) Calculate the coefficient of correlation from the information in (a). Write the H_o and H_a. Then, make a decision about the significance of the coefficient of correlation. c) Wha

### Hypothesis Testing: T-test

The average length of time for students to register for classes at a certain college has been 50 minutes. A new registration procedure is being tried. A random sample of 12 students resulted in an average registration time of 42 minutes with a standard deviation of 11.9. Assume the distribution of registration times are norma

### Summary of Attached Case Study

- Summarize the study from the article and thoroughly explain the use of the t test or chi square and how it is (or is not) important to healthcare and healthcare managers. - Provide a clear example of the use of tests for significance in a healthcare management setting. See attached PDF.

### Hypothesis Testing - Two-Tailed T-test

A psychiatrist hires you to study whether her clients self-disclosed more while sitting in an easy chair or lying down on a couch. All clients had previously agreed to allow the sessions to be videotaped for research purposes. You randomly assigned 10 clients to each condition. The third session for each client was videotaped an

### Nutrition Education Programs

See the attachment. Nutrition education programs, which teach their clients how to lose weight or reduce cholesterol levels through better eating patterns, have been growing in popularity. The nurse in charge of one such program at a local hospital wanted to know whether the programs actually work. A random sample of 33 clien

### Statistics and Hypothesis Testing Problems

1. True or False? A hypothesis test is a process that uses population parameters to test a claim about about a sample statistics. 2. Use the given statement to represent a claim. Write its complement and state which is Ha and which is H0. 3. Determine whether the hypothesis test with the given null hypothesis listed below is

### Summary statistics, t test, Regression and Correlation: Silver's Gym and Body Fat vs. Weight

You are hired as a statistical analyst for Silver's Gym and your boss wants to examine the relationship between body fat and weight in men who attend the gym. After compiling the data for weight and body fat of 252 men who attend Silver's Gym, you find it relevant to examine the statistical measures and to perform hypothesis tes

### I need help with the following

Data set: two univariate data sets Use the World Bank's data website, I need to: - Pick out two variables that have to do with Economics or Business. For instance, this can include things such as GDP, GDP growth, agricultural production, imports, exports, trade deficit, employment, etc, but not things such as life expectanc

### Usability Study

Usability Study Part of a usability study to assess voting machines measured the time on task (TOT) of voters casting ballots (efficiency). Specifically, the data are for the same ballot cast on two different voting machines at the same location (called a precinct). Your job will be to perform a "t" test on these data and draw

### Forecast temperatures

Assume that you want to use a 0.05 significance level to test the claim that paired sample data come from a population for which the mean difference is Ud = 0. Find (a) d-, (b) Sd, (c) the t test statistic, and the critical values. Listed below are predicted high temperatures that were forecast before different days. Predi

### Choose ANOVA or t-test Analysis

A researcher was interested in the emotional effects of music on exam performance. Before their exam, a professor took one group of students into a room in which calming music was played. A different group of students were taken to another room in which new wave hard rock was being played. The students then took the exam and the

### Paired-samples T-test

The Stroop task is when color words are printed in the wrong color; for example, the word red might be printed in the color blue. The conflict that arises when we try to read the words, but are distracted by the colors, increases our reaction time and decreases our accuracy. Several researchers have suggested that the Stroop eff