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Student's t-Test

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

T-Distribution and Standard Normal Distribution

In what ways is the t distribution similar to the standard normal distribution? In what ways is the t distribution different from the standard normal distribution? How does the formula for the t test differ from the formula for the z test?

Question about Independent Sample T Test for Mean

In testing the equality of the two means below, what is the test statistic? (Use the unequal variances formula). Sample 1 Sample 2 Sample size 9 12 Sample mean 80 115 Sample variance 550 100 A) -4.20 B) -2.31 C) -0.18 D) -0.50

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

Hypotheses testing for insurance data using t test

C. An auditor reviewed 25 oral surgery insurance claims from a particular surgical office, determining that the mean out-of-pocket patient billing above the reimbursed amount was $275.66 with a standard deviation of $78.11. (a) At the 5 percent level of significance, does this sample prove a violation of the guideline

One sample t test example problems

I am stumped on the following problem and could use some help quickly. Please provide guidance on how to solve the problem. 1) The probability of default on a certain type of commercial loan is 0.10. If a bank makes 100 of these loans, what is the probability that at least 16 will default? A) 0.0475 B) 0.0228 C) 0.0336

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

One Sample Hypothesis Testing for base ball data set.

Using ratio or interval numerical data from the following data set develop one research question from which you will formulate a research hypothesis. The research question should pertain to the below test. Conduct a test of hypothesis to determine whether the mean salary of the teams was different from $80.0 million. Use the

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

T test statistic

A recent article in a computer magazine suggested that the mean time to fully learn a new software program is 40 hours. A sample of 100 first-time users of a new statistics program revealed the mean time to learn it was 39 hours with the standard deviation of 8 hours. At the 0.05 significance level, can we conclude that users le

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

Samples- Perform hypothesis testing and Perform a t-test

Perform hypothesis testing on one variable's data. (Choose either the intrinsic or extrinsic column.) Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, determining the appropriate critical value, selecting the test statistic and determining its value from the sample

T Test to Calculate the Null Hypothesis

To test the null hypothesis that the mean waist size for males under 40 years equals 34 inches versus the hypothesis that the mean differs from 34, the following data were collected: 33, 33, 30, 34, 34, 40, 35, 35, 32, 38, 34, 32, 35, 32, 32, 34, 36, 30. Calculate the t* -value of the test statistic.

Determining Null Hypothesis for Dependent Sampling Claim

You plan to test the dependent sampling claim: "a particular weight loss program is effective in weight reduction." What would be the null hypothesis, if d=X after −X before? A) Ho: μd = 0 B) Ho: μd = 0 (≥) C) Ho: μd ≠ 0 D) Ho: μd = 0 (≤)

T Test for Mean and 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

One sample t test for mean

A manufacturer of flashlight batteries took a sample of 13 batteries from a day's production and used them continuously until they failed to work. The life lengths of the batteries, in hours, until they failed were: 342, 426, 317, 545, 264, 451, 1049, 631, 512, 266, 492, 562, and 298. . At the .05 level of significance, i

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

One Sample T-Test for Baseball Data

During recent seasons, Major League Baseball has been criticized for the length of the games. A report indicated that the average game lasts 3 hours and 30 minutes. A sample of 17 games revealed the following times to completion. (Note that the minutes have been changed to fractions of hours, so that a game that lasted 2 hours a

Inferential Statistics

The Rocky Mountain district sales manager of JCM, Inc., a college book publishing company, claims that each of his sales representatives makes 40 calls on professors per week. Several reps said that this estimate is too low. To research the claim, a random sample of 28 reps revealed that the mean number of calls made last week

Independent sample t test

A sample of 40 observations is selected from one approximately normal population. The sample mean is 102 and the sample standard deviation is 5. A sample of 50 observations is selected from a second source. The sample mean is 99 and the standard deviation is 6. Conduct a hypothesis test using the .04 level of significance to

Five-Step Hypothesis-Testing Procedure

As part of a study of corporate employees the director of human resources for PNC. Inc. wants to compare the distance traveled to work by employees at their office in downtown Cincinnati with the distance for those in downtown Pittsburgh. A sample of 35 Cincinnati employees showed they travel a mean of 370 miles per month, with

T-Test and Comparison Distribution

What is the comparison distribution in a t test for independent means? Explain the logic of going from scores in two samples to an estimate of the variance of this comparison distribution. Why is the mean of this distribution 0?

Independent sample t test

Twenty students randomly assigned to an experimental group receive an instructional program; 30 in a control group do not. After 6 months, both groups are tested on their knowledge. The experimental group has a mean of 38 on the test (with an estimated population standard deviation of 3); the control group has a mean of 35 (with