Given a standard deviation of "1" and using the formula above, we can now plot how the
confidence intervals contract as sample size increases (FIGURE 3).
It should be emphasized that a 95%
confidence interval refers to the percentage of a large number of
confidence intervals, computed from random samples of a given size, that can be expected to include the true population mean.
For example, with a planning value of [[??].sup.2] = .1 and a desired
confidence interval width of [??] = .2, the required sample size is about 135, but with a planning value of [[??].sup.2] = .2, the sample size requirement jumps to 202.
Coverage Probability and Expected Length of Fuzzy
Confidence Interval. For an interval estimator [L(R), U(R)] of a true parameter d, the coverage probability of [L(R), U(R)] is the probability that the random interval [L(R), U(R)] covers [theta].
Two-factor ANOVA tested: HP depending VARIETY; STRESS Analysis of variance for the height of the plant Source DL SC CM F P VARIETE 3 54,8830 18,293 274,91 0,000 STRESS 4 23,7965 5,9491 89,40 0,000 Erreur 32 2,1295 0,0665 Total 39 80,8090
Confidence interval 95% Varietes moyenne BIDI 7,360 (-*) GTA 5,760 (-*) VITRON 4,840 (*-) WAHA 4,260 (-*) 5,000 6,000 7,00 8,000
Confidence interval Stress moyenne N1 6,663 (-*--) N2 5,988 (--*-) N3 5,550 (-*--) N4 5,225 (--*-) N5 4,350 (--*--) 4,200 4,900 5,600 6,300 7,000 Annex 2
Finally, the adaptive kernel estimation consist in compute a
confidence interval for the median using an estimate of the standard error based on adaptive kernel density estimator, a good approximation of the true density with small samples (Wilcox, 2005).
Statistical and clinical significance, and how to use
confidence intervals to help interpret both.
With z defined as the (1 - [alpha]/2)th quantile of the standard Normal distribution, the GBA
confidence interval will have the form
The odds ratio and 95%
confidence interval for only cigarette smokers were 3.5(CI=2.9-4.2), respectively which, means that the cigarette smokers were at a 3.5 times more risk of developing bladder cancer as compared to non smokers.
But some products did not perform as well as others and had very broad 90%
confidence intervals for both AUC and [C.sub.max].
Induced percentile left censoring slightly reduced the length of the
confidence interval estimates for Mill B (0.0008 to 0.0013 inches; 0.0203 to 0.0330 mm) with minor increases in the lower bound of the interval (0.0001 to 0.0003 inches; 0.0025 to 0.0076 mm).
Unfortunately, computing
confidence intervals for effect sizes is typically more complex than computing
confidence intervals for parameter estimates such as means.