# null hypothesis

1. ### T Test word problem! HELP

im going crazy trying to figure out this problem; please help! 2. Assume that we drew a random sample of 300 women who had recently graduated from USC. All of these women worked full time in 2018. They earned an average salary of $42,167 (s.d. =$26,413). Based on data from the US Census...
2. ### A Hypothesis testing problem

I have been facing some doubts regarding the problem given below. Firstly, if this problem is a Z-test or a T-test? Secondly, what should be the standard deviation ? sigma =? Here is my attempted solution, Please help.
3. ### Null Hypothesis

I am doing a research study and I am collecting data from Hotels. I am confident that the business models of the hotels ARE NOT suited for today's networked economy (beginning premise). What would my Null hypothesis be? Ho1: The business models in the hotel industry are suited for the current...
4. ### We did an experiment and don't know how to start/proceed with statistics?

We had to do an experiment in my research methods class. Me and my group did an experiment where we tested if participants remembered words better with or without pictures that match the words. So now we have two sets of data: One set with the number of words they remembered and one set with the...
5. ### SOS action research project question

Firstly, I am grateful for any assistance. I am a novice who tries hard :yup: I am trying to write up the results section for a report and have completed a paired t test and Cohen's d using pre and post data sets from same group: 35 students I have completed the test and worked the math...
6. ### Example Research Questionthe null hypothesis

Provide an example of a research question in which you must test if the mean value of a variable is equal to its historical value and describe the null hypothesis
7. ### Null Hypothesis

I am new to Statistics and using Chi Square test in R. My output is : X-squared = 4.5765, df = 2, p-value = 0.1014 How do i conclude if Null Hypothesis is rejected or not. Also, if the input data is dependent or independent? Kindly advise. Thanks a lot!
8. ### Stata: Test that the difference between two groups = -1

Does anyone know how to test the hypothesis that the difference between people without and with kids = -1 per night in Stata? I have the data set with kids as a dummy variable, but can't figure out where to start.
9. ### Is the Null Hypothesis ... ?

If the alternative hypothesis is mu>13 then what is the null? Is it a) mu<=13 or b) mu=13 I've seen both a) & b) so what's the rationale for each one?
10. ### Two-sided test Hypothesis

2. In 18 patients with Everley's syndrome, the mean level of plasma phosphate was 1.7 mmol/l (millimoles per liter) with a standard deviation of 0.8 mmol/l. If the mean level in the general population is 1.2 mmol/l, is there a statistically significant difference between the general population...
11. ### Help with hypothesis forming

Hi All, I am newbie to statistics. When I read the literature regarding null hypothesis, I understand that the null hypothesis should always include equals to sign (= , <=, >=). In my research, i am trying to prove that a variable is equal to zero in all my experiments. I am confused about...
12. ### Urgent: Hypothesis Testing with unknown standard deviation

Hi, I'm having a lot of trouble figuring out this problem without knowing the standard deviation. Please if anyone could help me that would be very much appreciated. Thank you! I also don't know how to calculate anything other than a 95% confidence interval. A national survey conducted in...
13. ### Sample Mean and Standard Deviation affects results to support reject Null Hypothesis

Hi All, I'm pretty new to Hypothesis Testing and I've come across a question I'm not sure of and was hoping someone could explain it. Suppose we wish to test H0: µ = 15 , HA: µ ≠15. Which of the following possible sample results give the most evidence to support HA? And the options...
14. ### Chi Square for Likert Scale in Single Sample

Evening All, I do hope someone can shed some light on my fog of the chi square. I conducted a single sample survey using Likert Scale scored 1-5 (1=Strongly Agree to 5=Strongly Disagree) to survey employees in medical practices on leadership behaviors during a major transition. The goal was...
15. ### Comparing negative binomial model to the null model with offsets

Hi there, I have a negative binomial model of count data with an offset (total counting effort) in R: L1<-glm.nb(counts~offset(log(total.counts))+temperature, link='log', data=dat) and I want to compare it to the null model. Am I right in thinking I can just do...
16. ### Hypothesis Testing

Can someone please explain this? How did that conclusion arrive? P(Type I error) = P(reject H0 | H0 is true) = P(X1 ≤ c, X2 ≤ c | N = 16) = cC2 / 16C2 = c(c-1)/240 What if it was P(Type I error) = P(reject H0 | H0 is true) = P((X1+X2)/2 ≤ c | N = 16) would the equation be different?
17. ### Hypothesis Testing for Standard Deviation

Hello! Attempting to complete this problem: -- The observations (volume in m^3/ha) of 10 prism plots from a given forest type are summarized as follows: sample mean = 420 m^3/ha "10" on top of the ∑ and "i-1" below the sigma, with "x^2" beside it = 1,778,400 (m^3/ha)^2 Using the...
18. ### Null and Alternative Hypothesis question

Hey guys I am really stuck on this one question and have no way to go about it. I would really appreciate any help I could get. Question 4 A sociologist believes that women sleep longer per night on the weekend than men. Sixty one people were surveyed. The following summary statistics were...
19. ### Null Hypothesis Rules: Can no difference be the alternative hypothesis?

For his dissertation a colleague has developed a software tool and has the expectation (hypothesis) that people can complete the task with the software tool without taking longer than the older, manual method. He has to write up his hypotheses with null and alternative hypotheses. He asked me if...
20. ### Multivariate Normality accepted at 5% significance level but rejected at 1% ??

Hi, I am new to this forum. I am trying to test whether a set of variables in the data follow multivariate normal distribution. I found Mardia's test for this and below is the summary of the results : Mardia Skewness 58.29 <.0001 Mardia Kurtosis 2.43 0.0149 Henze-Zirkler T 7.52 <.0001...