What is a null hypothesis? a. A hypothesis that states there is an effect or relationship in the population b. A hypothesis that states there is no effect or relationship in the population c. A hypothesis that is always rejected in hypothesis testing d. A hypothesis that supports the researcher's prediction

What is a null hypothesis? a. A hypothesis that states there is an effect or relationship in the population b. A hypothesis that states there is no effect or relationship in the population c. A hypothesis that is always rejected in hypothesis testing d. A hypothesis that supports the researcher's prediction

Calculus: Early Transcendentals

8th Edition

ISBN:9781285741550

Author:James Stewart

Publisher:James Stewart

Chapter1: Functions And Models

Section: Chapter Questions

Problem 1RCC: (a) What is a function? What are its domain and range? (b) What is the graph of a function? (c) How...

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Tourism is extremely important to the economy of Florida. Hotel occupancy is an often-reported measure of visitor volume and visitor activity (Orlando Sentinel). Hotel occupancy data for February in two consecutive years are as follows. Current Year Previous Year OccupiedRooms 1,470 1,458 TotalRooms 1,750 1,800 (a) Formulate the hypothesis test that can be used to determine if there has been an increase in the proportion of rooms occupied over the one-year period. (Let p1 = population proportion of rooms occupied for current year and p2 = population proportion of rooms occupied for previous year.) H0: p1 − p2 ≤ 0 Ha: p1 − p2 > 0 H0: p1 − p2 ≠ 0 Ha: p1 − p2 = 0 H0: p1 − p2 = 0 Ha: p1 − p2 ≠ 0 H0: p1 − p2 < 0 Ha: p1 − p2 = 0 H0: p1 − p2 ≥ 0 Ha: p1 − p2 < 0 (b) What is the estimated proportion of hotel rooms occupied each year? current ( ) previous ( ) (c) Calculate the test statistic. (Round your answer to two decimal places.) (…
Burnout. According to a recent survey 45% of health care workers ages 18-29 reported feeling burnout from their jobs. Researchers believe that the level of burnout among older workers is even higher than that of younger workers. To test this belief they collected data from a random sample of 237 healthcare workers ages 50-64, and observed that 55% of healthcare workers in this age group reported feeling burnout from their jobs. Which of the following describes the null hypothesis for this study? 1). Null hypothesis: p=0.55 2) Null hypothesis: p=.45 3) Null hypothesis: p>0.55 4) Null hypothesis: p>0.45
In a study designed to test the "truth" to the theory that, on average, U.S. adults gain weight between Thanksgiving and January a research team looked at responses from 8 randomly selected U.S. adults. The subjects were weighed (lb) on the day before Thanksgiving and again on January 3rd The raw data are found in Table 1. Let ? = 0.025 Pre-Thanksgiving 168.2 173.5 164.3 166.4 167.6 164.9 172.1 169.8 Jan. 3rd 173.3 159.9 175.4 172.1 174.8 169.7 177.3 164.5 Diff 5.1 -13.6 11.1 5.7 7.2 4.8 5.2 -5.3 C) The point estimate for the true standard deviation of the weight gain that U.S. adults have from Thanksgiving until Jan. 3 is: E) The test statistic for this data set is F) The P-value for this study is:
Question: A region's department of transportation is deciding whether to increase overnight traffic patrols for a stretch of expressway within the region. The residents who live near the expressway have complained that drivers travel faster at night than during the day. Several years ago, the department tested the claim that the population mean speed of drivers who travel on that stretch of expressway at night is greater than the population mean speed of drivers who travel during the day. Although the results were inconclusive, the department has access to the population standard deviations. The department assumes that the population standard deviation is 4.11 mph for drivers traveling at night and 3.92 mph for drivers traveling during the day. The department decides to conduct the test again by installing an automated speed gun on the stretch of expressway that randomly selects vehicles and records their speed. One sample contains the speed, in miles per hour, of the cars driving…
Short answer. You are conducting a study on an effective therapy for borderline personality disorder (BPD). Your subjects are randomly assigned to one of three types of therapy: 20 sessions of CBT, 20 sessions of DBT, and 20 sessions of psychoanalysis. Participants are given the Diagnostic Interview for Borderlines-Revised (DIB-R) before and after the 20 therapy sessions, to assess treatment efficacy. Based on the literature around BPD, you hypothesize that the DBT group will see the greatest improvement in DIB-R scores. 1) What measure of central tendency should you use to assess the dependent variable? And what is a potential confounding variable in this case? 2) What is your null hypothesis? What is your alternative hypothesis? 3) Is it directional or non-directional? and what statistical test would you use to assess your data? Please Answer Questions Completely Do Not Leave Questions Unsolved
Cat Ownership and Schizophrenia Could owning a cat as a child be related to mental illness later in life? Toxoplasmosis is a disease transmitted primarily through contact with cat feces, and has recently been linked with schizophrenia and other mental illnesses. Also, people infected with Toxoplasmosis tend to like cats more and are 2.5 times more likely to get in a car accident, due to delayed reaction times. The CDC estimates that about 22.5% of Americans are infected with Toxoplasmosis (most have no symptoms), and this prevalence can be as high as 95 % in other parts of the world. A study' randomly selected 262 people registered with the National Alliance for the Mentally III (NAMI), almost all of whom had schizophrenia, and for each person selected, chose two people from families without mental illness who were the same age, sex, and socioeconomic status as the person selected from NAMI. Each participant was asked whether or not they owned a cat as a child. The results showed that…
Scenario: If 20 participants completed an attention task twice — once after consuming a sugar pill and once after consuming a pill that contained 25 mg nicotine, which test would be most appropriate? Assume data meets all assumptions for a parametric test, and that participant exposure to the sugar pill vs. nicotine pill were counterbalanced. Question: What is the research / alternate hypothesis for this scenario? Nicotine does not affect attention. Nicotine affects attention. Anxiety does not affect attention. Anxiety affects attention.
David McCandless, Lee Byron, and their team scanned more than 10,000 Facebook status updates and set out to learn more about the timing of relationship breakups. They found that there was a peak in breakups on Valentine’s Day and Mondays with a dip on Christmas Day. [Source: McCandless, D. (July 2010). The beauty of data visualization. TEDGlobal talks.] Suppose you are a researcher. You conduct a hypothesis test to determine whether the mean number of breakups on Sundays is lower than the mean number of daily breakups. Assume that the mean number of daily breakups is 10.3 breakups (the population mean). You obtain a sample of 10,000 Facebook status updates, which yields a sample mean of M = 11.4 breakups. Let μ denote the mean number of breakups on Sundays. Formulate your null and alternative hypotheses by selecting the appropriate values in the blue dropdown menus that follow. H₀: blank, blank, blank H₁: blank, blank, blank the test you…
David McCandless, Lee Byron, and their team scanned more than 10,000 Facebook status updates and set out to learn more about the timing of relationship breakups. They found that there was a peak in breakups on Valentine's Day and Mondays with a dip on Christmas Day. [Source: McCandless, D. (July 2010). The beauty of data visualization. TEDGlobal talks.] Suppose you are a researcher. You conduct a hypothesis test to determine whether the mean number of breakups on Sundays is lower than the mean number of daily breakups. Assume that the mean number of daily breakups is 10.3 breakups (the population mean). You obtain a sample of 10,000 Facebook status updates, which yields a sample mean ofM = 11.4 breakups. Let p denote the mean number of breakups on Sundays. Formulate your null and alternative hypotheses by selecting the appropriate values in the blue dropdown menus that follow. Ho: H1: The test you conduct is test.
A. Write the hypothesis and null you believe the researcher is testing. B. Make a claim about this hypothesis test; noting form, degree, and significance in yourclaim. C. Make a claim about the overall fit of the model (significance, variance explained). D. Discuss a plausible potential control variable you would want to include and the impact that you would speculate it to have on this relationship. (For example, what type of control is your variable, how will it alter the relationship between the DV and the IV, etc.).
Alzheimer’s disease increases in frequency with an increase in age and is responsible for deficits in memory, thinking, judgement and reasoning. Reports show that 10% of Americans over the age of 65 have Alzheimer’s disease. A researcher believes that this proportion is increasing over time and conducts a c hypothesis test. Out of the 100 Americans over the age of 65 in her sample, 15 of them have the disease. Is this enough evidence to show the researcher’s claim is true? Test at 0.05 alpha level.