Five Steps in a Hypothesis Test
Pulse rates for n = 35 women are available. Here are Minitab results for our hypothesis test:
When we evaluate the nullhypothesis, we can make 2 types of errors.
Before moving onto the second step of the hypothesis testing process, we need to take you on a brief detour to explain why you need to run hypothesis testing at all. This is explained next.
Most of the reports arguing for EMT and cancer stemcell correlation focus on the idea that an EMT phenotype drives acancer stem cell microenvironment that is characterized asCD44/CD24 in breast cancer, which isassociated with therapeutic resistance, tumor invasion and poorprognosis (,). As we observed in the current study,HER2 overexpression leading to STAT3 activation resulted inupregulation of CD44 expression. Furthermore, a recent study byOliverasFerraros concluded that a mesenchymalCD44/CD24 microenvironment in HER2overexpressed breast cancer was linked to resistance to Herceptintreatment ().
Test the appropriate hypothesis at the 5% level.
The level of statistical significance is often expressed as the socalled pvalue. Depending on the statistical test you have chosen, you will calculate a probability (i.e., the pvalue) of observing your sample results (or more extreme) given that the null hypothesis is true. Another way of phrasing this is to consider the probability that a difference in a mean score (or other statistic) could have arisen based on the assumption that there really is no difference. Let us consider this statement with respect to our example where we are interested in the difference in mean exam performance between two different teaching methods. If there really is no difference between the two teaching methods in the population (i.e., given that the null hypothesis is true), how likely would it be to see a difference in the mean exam performance between the two teaching methods as large as (or larger than) that which has been observed in your sample?
The alternative hypothesis can bedirectional or nondirectional.“Eating oatmeal lowers cholesterol” is a directional hypothesis; “Amountof sleep affects test scores” is nondirectional.
Test at ALPHA=.05 the hypothesis that the true weight is 140 lb.
Sarah predicted that her teaching method (independent variable: teaching method), whereby she not only required her students to attend lectures, but also seminars, would have a positive effect (that is, increased) students' performance (dependent variable: exam marks). If an alternative hypothesis has a direction (and this is how you want to test it), the hypothesis is onetailed. That is, it predicts direction of the effect. If the alternative hypothesis has stated that the effect was expected to be negative, this is also a onetailed hypothesis.
As such, by taking a hypothesis testing approach, Sarah and Mike want to generalize their results to a population rather than just the students in their sample. However, in order to use hypothesis testing, you need to restate your research hypothesis as a null and alternative hypothesis. Before you can do this, it is best to consider the process/structure involved in hypothesis testing and what you are measuring. This structure is presented .
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Statistical hypothesis testing  Wikipedia
Identify the critical value suitable for conducting a twotail test of the hypothesis at the 2% level.

Hypothesis  Type I And Type Ii Errors  Hypothesis
The hypothesis test that followed ended with a decision of "reject H(O)".

Hypothesis Tests  Statistics and Probability
Test the null hypothesis that the new ball does not improve a bowler's average at the 5% level of significance.
Test of hypothesis  SlideShare
BT474 wildtype, SKBR3 wildtype and MCF7 wildtypecells were obtained from the American Type Culture Collection(ATCC). They were maintained in a monolayer culture in DMEM/F12(Dulbecco’s modified Eagle’s medium) with 10% fetal bovine serum,2.5% Lglutamine and 0.5% penicillin/streptomycin. The MCF7HER2(MCF7 cells transfected with HER2) cell line was a generous gift ofDr C. Kent Osborne (Baylor College of Medicine, Houston, TX).MCF7HER2 cells were maintained in a monolayer culture in DMEM 1Xwith 10% fetal bovine serum, 2.5% Lglutamine, 0.5%penicillin/streptomycin, and G418 (400 g/ml).
How to Plan and Write a Testable Hypothesis  wikiHow
Suppose we conduct an experimentto test whether a new drug is effective in reducing cholesterol, and, afterfollowing our steps for hypothesis testing, we are unable to reject H_{0}.There are 2 reasons this might happen:
Which type of hypothesis cannot be tested? Why does …
In statistics terminology, the students in the study are the sample and the larger group they represent (i.e., all statistics students on a graduate management degree) is called the population. Given that the sample of statistics students in the study are representative of a larger population of statistics students, you can use hypothesis testing to understand whether any differences or effects discovered in the study exist in the population. In layman's terms, hypothesis testing is used to establish whether a research hypothesis extends beyond those individuals examined in a single study.
Hypothesis Testing: Type I or Type II Error  BrainMass
Initially we tested the effect of STAT3 inHER2positive breast cancer. We wished to determine whether thecoexpression of HER2 and ER induced STAT3 phosphorylation, andwhether pSTAT3 promotes stemlike cell phenotype in the breastcancer model. To this end, the basal expression of STAT3 and stemcell markers were examined in various human breast cancer celllines by western blot analysis and realtime PCR. STAT3 wasphosphorylated in MCF7HER2 cells, but not in MCF7 wildtype(). In addition, STAT3 wasphosphorylated in BT474 as well as at very low level in SKBR3. MCF7wildtype lacks HER2 amplification and SKBR3 lacks ER. This isconsistent with previous data in which MCF7 WT did not typicallyshow phosphorylation of STAT3 (,).Moreover, we found that the stem cell markers, Oct4 and Sox2,were expressed in MCF7HER2 and BT474 cells, but not in MCF7wildtype and SKBR3 ().Realtime PCR analyses confirmed the upregulation of stem cellmarkers in HER2overexpressing, ERpositive cancer cells (). Our results support thehypothesis that HER2 overexpression and ER positivity promoteSTAT3 phosphorylation and induces the stem celllike phenotype.
Solved: Hypothesis testing and type, Mathematics
Transcription factor slug, which has been implicatedas a driver for the epithelialmesenchymal transition (EMT) wasupregulated in MCF7HER2 cells (), leading us to the hypothesis that, HER2 induced stem cellmarker expression and slug upregulation promoted the EMT phenotypein MCF7 cells. Realtime PCR analyses showed the gene expressionpattern matching with the mesenchymal microenvironment, showingsignificant upregulation in vimentin, slug and concurrentdownregulation of Ecadherin in MCF7HER2 compared with controlMCF7 wildtype (). In linewith the PCR data, western blot analyses revealed that epithelialmarker Ecadherin was downregulated, while mesenchymal makervimentin was upregulated in HER2 transfected MCF7 cells (). These results indicate that thesequential activations elicited by HER2 amplification converge intothe HER2pSTAT3stem cell markers  early EMT characteristics insignal pathways.