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# Student's t-Test

### Back Charges Evaluation: Example Problem

Please complete and show all work. An engineering firm is evaluating their back charges. They originally believed their average back charge was \$1800. They are concerned that the true average is higher, which could hurt their quarterly earnings. They randomly select 40 customers, and calculate the corresponding sample mean b

### Describe a real-world problem using a single sample t-test

The principal of your local school announces to the school-community group (of which you are a part) that funding will be cut next year if a higher percentage of the children in the 4th, 5th, and 6th grades do not perform at the expected level of proficiency on the state test. Your principal knows you are a graduate student and

### Statistics: t-test for two independent samples

1. One sample has SS= 35 and the second sample has SS=45. a) assume that n=6 for both, calculate the sample variance, and the pooled variance. b) assume that n=6 for one and n=16 for the other, calculate the two sample variances and the pooled variance. 2. A sample of n=10 people receive medication with pain tolerance and

### Single-Sample T test

Bring to mind a real-world situation or problem that could be addressed using a single-sample t test. Give a brief description of the real-world situation or problem you selected to address, the independent and dependent variables you would study, the statistical null and alternative hypotheses, a description of what inform

### Test Statistic for Significance of Correlation Coefficient

You are testing the null hypothesis that there is no linear relationship between two variables, X and Y. From your sample of n=10, you determine that r=0.80. a. What is the value of tstat? b. At the a=0.05 level of significance, what are the critical values? c. Based on your answers to a and b what statistical decision

### T Statistics

1. indicate whether the factor influence the numerator or denominator of the t statistic and determine whether the effect would be to increase the value of t or decrease the value of t if all other factors rmain constant. a) increase the variability of the scores b) increase the number of scores in the sample c) increase the

### Performing Hypothesis Tests on Two Samples: Example Problem

A study is conducted to compare mean cholesterol levels for individuals following a low carbohydrate diet for at least 6 months to individuals following a conventional (low fat, low calorie )diet for at least 6 months. test if there is a significant difference in mean cholesterol levels between the diet programs using a 5% level

### T-Test for Dependent Samples

Big Time Software Co. has developed a new version of it XD-3 software. They want to determine if the new version of XD-3 is faster then the old version. In a matched sample test they obtained the following results. Tester Old Version New Version 1 2.6 2.8 2

### 5 Step Hypothesis Test: Two Sample t-Test assuming both Equal and Unequal Variances

A company making plastic opitical components for bar code scanners was studying inconsistencies in an optical measurement called tilt. The company knew that scanners work best when tilt measurement is small. Two different types of locking mechanisms used in the mold produced the following units. Taper Locks Locki

### 5-Step Hypothesis Test: Two Sample t-Test

Using the Data Collection attached, perform the following statistical operations and compile your results in a Microsoft Word document: ? State a research (non-directional) hypothesis and a null hypothesis about the populations ? Determine the cutoff sample score of t at ±=.05 ? Calculate a mean and variance for each sampl

### T-test or Z-test

You want to determine if your widgets from machine 1 are the same as machine 2. Machine 1 has a sample mean of 2000.21 and a sample standard deviation of 6.1 and a sample size of 2. Machine 2 has a sample mean of 1998.76 and a sample standard deviation of 6.2 with a sample size of 2. With an alpha of .05 can we claim that the

### Inferences from Dependent Samples

Car Repair Costs Listed below are the costs in dollars of repairing the front ends and rear ends of different cars when they were damaged in controlled low-speed crash tests. The cars are Toyota, Mazda, Volvo, Saturn, Subaru, Hyundai, Honda, volkswagen, and Nissan. Contruct a 95% confidence interval of the mean of the differe

### Statistical Sampling for AIU's survey responses: two-tailed test, critical value

Using AIU's survey responses from the AIU data set, complete the following requirements in the form of a report: Perform a two-tailed hypothesis test on both the intrinsic and the extrinsic variable's data, using a .05 significance level. Begin by creating a null and an alternate statement. Use Microsoft Excel to process you

### Statistics: Stem cell research, hypothesis, p-value, and sufficient evidence

Multiple myeloma or blood plasma cancer is characterized by increased blood vessel formulation in the bone marrow that is a prognostic factor in survival. One treatment approach used for multiple myeloma is stem cell transplantation with the patient's own stem cells. The following data represent the bone marrow microvessel den

### Statistics: Perform a two-tailed hypothesis test using AIU's survey responses

See attached data set file. Using AIU's survey responses from the AIU data set, complete the following requirements in the form of a report: Perform a two-tailed hypothesis test on both the intrinsic and the extrinsic variable's data, using a .05 significance level. Begin by creating a null and an alternate statement. Use

### Hypothesis Test for AIU data 1001B: Job satisfaction survey

Perform a two-tailed hypothesis test on both the intrinsic and the extrinsic variable's data, using a .05 significance level. Begin by creating a null and an alternate statement. Use Microsoft Excel to process your data. Copy and paste the results of the output to your report in Microsoft Word. Identify the significance level, t

### Statistics Samples of AIU's survey responses; t-test and z-test

See attached data files. Using AIU's survey responses from the AIU data set, complete the following requirements in the form of a report: Perform a two-tailed hypothesis test on both the intrinsic and the extrinsic variable's data, using a .05 significance level. Begin by creating a null and an alternate statement. Use Mic

### Statistics: Hypothesis test on both the intrinsic and the extrinsic variable's data of AIU

See attached data set. Using AIU's survey responses from the AIU data set, complete the following requirements in the form of a report: Perform a two-tailed hypothesis test on both the intrinsic and the extrinsic variable's data, using a .05 significance level. Begin by creating a null and an alternate statement. Use Micr

### Independent sample T test .

Period Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Mon :Group A 10 20 25 25 35 40 Tues: Group A 15 25 25 25 35 25 Wed: Group B 20 28 25 25 35 25 Thur: Group B 25 32 35 25 35 25 50 students were present each day Do a T test to indicate the significance between those students who had homework assignments

### T- test using ANOVA

I don't think I would use an anova because I don't have two levels on conditions or two independent variables. I think I would need to use the t-test then. I could divide the employees into two equal groups and compare the means of the two groups. So, my question would be, what would your independent variables be? Employee

### Statistics Hypothesis Testing Questions

You will be asked to determine the correct decision (Reject Ho or Fail to Reject Ho) for each of the following tests of hypotheses. 1. A hypothesis test at the 0.05 level of significance with a p-value for the sample of 0.105. 2. A hypothesis test at the 0.025 level of significance with a p-value for the sample of 0.00

### T test for comparing IQ of males and females

Calculate and compare the means for IQ as a dependent variable and gender as your independent variable. Do you think males and females differed in their IQ scores? Why? Male mean= 99.33 N= 55 Std Dev= 13.192 Range= 62 Kurtosis=.224 Skewness=.451 Female Mean=101.82 N=33 Std Dev=12.677 Range=45 Kurtosis=-.731

### Statistics T-distribution: A sample size approaches infinity; mayoral election is contested

1. As a sample size approaches infinity, how does the student's t distribution compare to the normal z distribution? When a researcher draws a sample from a normal distribution, what can one conclude about the sample distribution? Explain. 2. A mayoral election race is tightly contested. In a random sample of 1,100 likely vot

### The difference between t-tests and z-tests

In drawing an inference using a single mean in hypothesis testing, you often have a choice between doing a z-test or a t-test. Many researchers will always choose to do the t-test even under circumstances where the z-test would work as well. Explain why the t-test was developed and why it is preferred.

### Statistics: AIU survey responses; two-tailed hypothesis test, t-test, z-test,

See attached data file. Using AIU's survey responses from the AIU data set, complete the following requirements in the form of a report: Perform a two-tailed hypothesis test on both the intrinsic and the extrinsic variable's data, using a .05 significance level. Begin by creating a null and an alternate statement. Use Mic

### Hypothesis test for the population mean:T-test

A rental agent claims that the mean monthly rent, , for apartments on the east side of town is less than \$675 . A random sample of 18 monthly rents for apartments on the east side has a mean of \$661, with a standard deviation of \$24 . If we assume that the monthly rents for apartments on the east side are normally distributed, i

### Statistics Problem

Question 8. A sample of scores on an examination given to both makes and females in MAT 500 is: Males 72, 69, 98, 66, 85, 76, 79, 80, and 77 Females 81, 67, 90, 78, 81, 80, and 76 At the .01 level of significance, is the mean grade of the female students higher than that of the males?

### Independent Sample t test nonnumerical data

I am having a hard time understanding how to perform t-tests in nonnumerical data. A. Perform two t - tests to determine if there is a difference in your spending category based on Card Type or Reward Type. Do people who get World Points spend more than those who get Gas Rebates on your Spend type? Do people with Master

### Independent Sample t test credit cards

Using the credit card data that appears on the next tab, analyze Airline Spend. Perform two t-tests to determine if there is a difference in your spending category based on Card Type or Reward Type. Do people who get World Points spend more than those who get Gas Rebates on your Spend type? Do people with Master Cards spend

### Interpretation of Descriptive Statistics: Nurse Example

An insurance company is trying to determine if there is a significant difference in the average number of sick days that registered nurses and nurse practitioners use per year. The data analysis provided the following output. Two sample T for registered nurses vs nurse practitioners: N