Student f-test

Student f-test A statistical test to establish if there is a significant difference between two mean values, taking account of the uncertainties associated with both values. 

Fig. (9). Restored delayed footpad reaction (DFR) againstMeth A tumor antigen following CVS treatment [44]. BALB/c mice were injected s.c. with 1 x 10 Meth A cells in the right flank on day 0 and rechallenged i.v. cm day 9. The primary tumor was removed on day 11. CVS (50 mg/kg) or PBS was injected i t. once into the primary tumor on day 3. Mitomycin C-treated Meth A was injected into the footpad on days 9,16 or 23. Footpad swelling was measured 24 h after the elicitation. Each value is the mean SD for ten mice, unprimed age-matched normal mice that were not primed the Meth A tunror. a Tumor unprimed mice were s.c. injected with CVS on day 3 and DFR was elicited on day 9.. significantly different (students f-test, p<0.001) from the correspondingly timed PBS group.

CDF1 mice were injected with CVS (50 mg/kg, six times, s.c.) on days -14 to -1, and treated with 5FU (550 mg/kg, i.p.) on day 0. Bacterial counts are mean SD. Detected No. number of bacte-ria-detected mice in their organs/number of mice used. Bacterial No. mean SD of bacterial number in their organs. a p < 0.01, and b p < 0.05 versus the group given 5FU alone by students f-test. 

The test is also known as the independent samples /-test or the Student f-test . The use of numerous apparently distinct names for exactly the same test is a handy device used by statisticians to keep everybody else in a constant state of uncertainty. 

A common statistical measurement is the Student f test or Student s t test. Student was the pseudonym of W. Gossett, an eminent mathematician. 

In other cases of determining whether a transfer has been successful involves the use of sophisticated statistical means (Table 16-4) such as the Student f-test, testing of equality of means from two groups (two sample... 

The total radioactivity recoverable from the TLC plates for both groups and the patient with Refsum s disease is compared in Figure 4.1. A quantitative difference is apparent, there being approximately 60% more radioactivity recoverable in the ichthyosis group than in the normals. This difference was significant (P<0.01) according to the Student f test. In the patient with Refsum s disease an increase of 130% compared to normal was noted. 

In this experiment students standardize a solution of HGl by titration using several different indicators to signal the titration s end point. A statistical analysis of the data using f-tests and F-tests allows students to compare results obtained using the same indicator, with results obtained using different indicators. The results of this experiment can be used later when discussing the selection of appropriate indicators. 

In this experiment students measure the length of a pestle using a wooden meter stick, a stainless-steel ruler, and a vernier caliper. The data collected in this experiment provide an opportunity to discuss significant figures and sources of error. Statistical analysis includes the Q-test, f-test, and F-test. 

Students use a commercial diluter to prepare five sets of dilutions of a stock dye solution (each set contains ten replicates) using two different diluters. Results are compared using f-tests and F-tests. 

There are two common methods for comparing results (a) Student s -test and (b) the variance ratio test (F-test). 

Student s f-test. This is a test1 used for small samples its purpose is to compare the mean from a sample with some standard value and to express some level of confidence in the significance of the comparison. It is also used to test the difference between the means of two sets of data x, and x2. 

The superscript a,b,c,d,e,f,g,h indicates significance difference from 1,2,3,4,5,6,7,8 groups, respectively. The data is analyzed by one-way ANOVA(F-test) followed by Newmann Keul s Studentized range test... 

The p-value for the f-test is found in the pValue variable in the pvalue data set, where the variable test is equal to Student s t. ... 

Assessments of risks associated with the use of chlorpyrifos insecticide products for workers have been made. The assessments are based on the results of field studies conducted in citrus groves, a Christmas tree farm, cauliflower and tomato fields, and greenhouses that utilized both passive dosimetry and biomonitoring techniques to determine exposure. The biomonitoring results likely provide the best estimate of absorbed dose of chlorpyrifos, and these have been compared to the acute and chronic no observed effect levels (NOELs) for chlorpyrifos. Standard margin-of-exposure (MOE) calculations using the geometric mean of the data are performed however, probability (Student s f-test) and distributional (Monte Carlo simulation) analyses are deemed to provide more realistic evaluations of exposure and risk to the exposed population. 

The results from using the Student s f-test for a distributional analysis are presented in Table 4. These results indicate the probability of a given worker in the listed scenario exceeding the NOEL of the toxicity endpoint. The probability of exceeding the LOEL and of thus experiencing a depression of plasma cholinesterase activity is not given (except for chronic exposure scenarios in the "100 ug/kg bw/day" column). Hence, even these probabilities may be considered to be conservative and not fully representative of the probability of a worker actually experiencing a toxic effect. 

Influence on sensitivity can be tested by Student s f-test. The null hypothesis is H0 Sff = S ] 1 where SA]al is the sensitivity under ideal, i.e. robust conditions and Sr]f the sensitivity under the influence of i interferents and j factors ... 

The test to determine whether the bias is significant incorporates the Student s /-test. The method for calculating the t-test statistic is shown in equation 38-10 using MathCad symbolic notation. Equations 38-8 and 38-9 are used to calculate the standard deviation of the differences between the sums of X and Y for both analytical methods A and B, whereas equation 38-10 is used to calculate the standard deviation of the mean. The /-table statistic for comparison of the test statistic is given in equations 38-11 and 38-12. The F-statistic and f-statistic tables can be found in standard statistical texts such as references [1-3]. The null hypothesis (H0) states that there is no systematic difference between the two methods, whereas the alternate hypothesis (Hf) states that there is a significant systematic difference between the methods. It can be seen from these results that the bias is significant between these two methods and that METHOD B has results biased by 0.084 above the results obtained by METHOD A. The estimated bias is given by the Mean Difference calculation. 

The quantity of RNA extracted from FFPE cell/tissue sections by the heating and nonheating methods, and extracted from fresh cell/tissue embedded in OCT without fixation, was comparable, showing no significant difference for all yields of RNA by Student s f-test, with the exception of one sample, MDA cells fixed in formalin for 24 h (p < 0.05). 

Concentrations significantly reduced (Student s f-test, P<0.05) compared with snails on L diet. 

Continuous Student s unpaired f-test Student s paired f-test ANOVA Paired ANOVA... 

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