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Student's t-Test

Which statistical test to use?

You want to compare differences in sales dollars (DV) for 43 employees before and after they have attended a motivational seminar. Since comparing differences is the goal, I presume that you are going to compare the means of a pre-post test of the 43 employees. Okay, I was going to say that this is the answer but lets be hon

Hypothesis Test: Mean vs. Hypothesized Value

1. To reduce operating costs, First UP Bank wants to make sure that the loan department in its branches manage the number of courier packages sent out to appraisers etc. to 15 or less every week. The Bank examined the loan departments of 25 randomly chosen branches and the results show that an average of 14.2 packages with a sta

Independent sample t test ..

A marketing firm asked a random set of married and single men as to how much they were willing to spend for a vacation. At = .05, is a difference in the two amounts? Married men Single men Sample size 50 70 Mean spending 260 185 Sample variance 4500 9000 A) Yes, because the test value 5.07 is outside the interval

Descriptive Statistics (Inferences from Matched Pairs)

Question: Before and After Treatment Results: Captopril is a drug designed to lower systolic blood pressure. When subjects were tested with this drug,, their systolic blood pressure reading (in mm of mercury) were measured before and after the drug was taken, with the results given in the accompanying table (based on data f

This is a sample two-population write up, pooled t-test vs unpooled t-test.

In a study of the lizard Sceloporis occidentalis, researchers examined field-caught lizards for infection by the malarial parasite Plasmodium. To help assess the ecological impact of malarial infection, researchers tested 15 infected and 15 noninfected lizards for stamina, as indicated by the distance each lizard could run in 2

ANOVA versus a t-test

Please help with the following problem. Provide a step by step solution. How can you tell when you should use the ANOVA versus a t-test? What is one problem with using the ANOVA when the t-test is the appropriate data analysis?

Independent sample t test for comparison of mean. .

In the past, young women drivers have maintained a better driving record than young men drivers. An insurance company is concerned with the driving record of its insured customers. Specifically, it conducts a test for the number of speeding tickets received during the past year by drivers between the ages of 18 and 25. men

Independent sample t test for financial planner

1. A financial planner wants to compare the yield of income- and growth-oriented mutual funds. Fifty thousand dollars is invested in each of a sample of 35 income-oriented and 40 growth-oriented funds. The mean increase for a two-year period for the income funds is $1100 with a standard deviation of $45. For the growth‑

A Paired T-Test: The Effectiveness of Training

A group of 20 sales associates agree to go through a week-long sales class to improve their productivity. The amount of their sales are computed for one month before and one month after the training course. Sales # Before After 1 $ 33,766.65 $ 37,483.57 2 $ 52,827.74 $ 37,871.17 3 $ 26,654.23 $ 22,036.40 4 $ 21,7

T-test for improved productivity

A group of 20 sales associates agree to go through a week-long sales class to improve their productivity. The amount of their sales are computed for one month before and one month after the training course. Run the paired t-test to find out if: Is there evidence to suggest that the training course helps out sales peo

Hypothesis Test Using Megastat: T-Test for Computer Sales

A month of sales data are collected on sales of different types of computer products. Run the t-tests to determine: A. Is there a difference in the total sales numbers for laptops versus desktops? B. Is there a dfifference in the total sales numbers for components versus desktops? Laptop

Independent sample t test

A manufacturer claims that the mean lifetime of its fluorescent bulbs is 1050 hours. A homeowner selects 40 bulbs and finds the mean lifetime to be 1030 hours with a standard deviation of 80 hours. Test the manufacturer's claim. Use α = 0.05 1. State H0 2. State Ha 3. What is the claim? 4. What is the criti

One Sample Hypothesis

Need a suggestion for a One Sample Hypothesis from the following data set. Price Price($000) Age of Buyer Type 0=Domestic 1 = Import 15935 15.935 25 1 15546 15.546 26 1 17357 17.357 28 1 20047 20.047 28 1 17399 17.399 29 1 18021 18.021 29 1 15794 15.794 30 1 17968 17.968 30 1 18890 18.89 31 1 24609 24.609 31 1 1726

Independent Sample T-Test Problem

D) Silver Gym's aerobic class grew so large that the class had to be split in half and offered on two different nights. Silver also hired a new aerobic leader to handle the Tuesday night class, whereas an existing staff member continued to handle the Thursday night class. Concerned about customer satisfaction with the new leader

Level of Significance: Independent Sample T-Test for Comparison of Mean.

Serum ferritin is used in diagnosing iron deficiency. In a study conducted recently researchers discovered that in a sample of 28 elderly men the sample standard deviation of serum ferritin was 52.6 mg/L. For 26 younger men the sample standard deviation was 84.2 mg/L. At the .01 level of significance, do these data support th

T test for population mean

2. Suppose you want to test the claim that population mean miu=3.5. Given a sample size of n=34 and a level of significance of alpha=0.01, when should you reject Ho? 3. Find the standardized test statistic t for a sample with n=15, sample mean=8.7, s=0.8, and alpha =0.05 if Ho is less than or equal to 8.4. 4. Find the sta

Data loading and descriptive statistics

EXERCISE #1: DATA LOADING & DESCRIPTIVE STATISTICS. Imagine that stimulus students are asked to indicate how likely they are to use a new breakfast-food/ toothpaste combination. The rating scale ranges from 0 (no chance of using the product) to 100 (certain to use the product). Your trustworthy but confused lab assistant han

Statistics on engineering widget

The engineer in a widget factory wants to test out a new form of raw materials. So a batch of widgets are made in the old manner as a control group and then a batch are made with the new materials as a comparison. If the average widget weight is statistically the same on both sets, the new materials will be used. The weights

Hypothesis Test: T-test

Please see attachment. I need help with the highlighted parts. Hypothesis test for the difference of population means: t test Medical researchers interested in determining the relative effectiveness of two different drug treatments on people with a chronic mental illness established two independent test groups. The first gr

Two or More Sample Hypothesis Testing : Graphs, Tables and Data Analysis

Implement raw data tables and computations, using both graphical and tabular methods of displaying data and results The US economy is in crisis brought on by the financial markets, the deep slump of the housing, high unemployment, and the slowdown of consumer spending. This has caused problems for buyers and sellers in the

Correlation and regression

Members of the general adult population volunteer an average of 4.2 hours per week. A random sample of 20 female college students and 18 male college students produced the results given in the table below. Assuming that the variances of the time volunteered by females and males are equal, at the .01 level of significance, is t

Question about Confidence interval and t test

Part 1 Biting an unpopped kernel of popcorn hurts! As an experiment, a self-confessed connoisseur of cheap popcorn carefully counted 773 kernels and put them in a popper. After popping, 66 unpopped kernels were counted. A. Construct a 90% confidence interval for the proportion of all kernels that would not pop. 1. What

Z score and T test

Z test At a retail store, customer survey is South Dallas the average household income of 75 household showed $90K with standard deviation of $25K. At another store in North Dallas, the household income of 60 households surveyed showed $120K with standard deviation of $30K. At significance level of 0.07, can a research anal

Independent sample t test for comparing population means

1) Survey showed 75 new employees hired at one employment place had an average salary of $60K with standard deviation of $20K. At another employment place, the average income of 60 households surveyed showed $85K with standard deviation of $25K. At significance level of 0.05, can a surveyor conclude that population means are dif

Hypothesis testing

Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the afternoon shift than on the day shift. A sample of 54 day-shift workers showed that the mean number of units produced was 345, with a standard deviation of 21. A sample of 60 afternoon-shift workers

Means and Deviation

If 15 subjects take a pre-test and a post-test with a mean change score of 1.5, and if the standard deviation of the comparison distribution is calculated to be .5, what is the t score? A. 1.5/(15-1)=0.11 B. 1.5/15=0.10 C. 1.5/.5=3.00 D. 1.5/(.5(15-1)=0.21 A school counselor claims that he has developed a technique

Two-sample hypothesis tests

One group of accounting students took a distance learning class, while another group took the same course in a traditional classroom. At £ = .10, is there a significant difference in the mean scores listed below? (a) State the hypotheses. (b) State the decision rule and sketch it. (c) Find the test statistic. (d) Make a deci

The answer to Hypothesis testing : Five step method T test

In two independent samples, from populations that are normally distributed , x1 = 35.0, s1 = 5.8, n1 = 12 and x2 = 42.5, s2 = 9.3, n2 = 14. Using the 0.05 level of significance, test Ho:u1 versus H1:u1 = u2. 2. The product development team for a notebook computer company has shown picture A to a large sample of potential bu