Look where the confidence intervals fall to determine if there is a significant difference in means (i.e. non-zero) I have also looked at the Wilcoxon rank-sum but it is not giving very reasonable results due to the very heavily skewed distribution (e.g. the 75th == 95th percen...
The bias can be calculated from the target value of the manufacturer’s trueness control (CRM) according to the following equation [10]: (2)u(bias)=√(bias)2+(Sbias√n)2+u(Cref)2(2)u(bias)=(bias)2+(Sbiasn)2+u(Cref)2 (2) Where the bias is the % difference from the nomin...
However, if the study will only be useful if a significant difference is detected for smaller differences – say, a difference of 5% — the sample size must be larger to accommodate this needed precision. Similarly, if 5% is enough, and 3% is unnecessary, there is no need for a larger ...
Type II Error (False Negative): On the flip side, a Type II error happens when you fail to reject the null hypothesis when it’s actually false. This means you’re missing a real effect or difference because the data didn’t show it as significant. It’s as if you overlooked something...
To determine if a new social media platform is worth your time, check your competitor's engagement rates on those sites. First, visit the following sites to see if your competition has an account on these platforms: Facebook. Twitter. Instagram. Snapchat. LinkedIn. YouTube. Pinterest. Then,...
Decide how long you'll run the experiment. This will depend entirely on how long it usually takes to get conversions. If it usually takes a week to get a handful of conversions, let the test run for a month. You want to make sure your results are statistically significant. ...
If neither variation is significant, the variable you tested didn’t impact results, and you’ll have to mark the test as inconclusive. In this case, stick with the original variation or run another test. You can use failed data to help you figure out a new iteration on your new test....
Suppose Alex, a financial analyst, is curious as to whether some investors had advance knowledge of a company's sudden failure. Alex decides to compare the average ofdaily market returnsbefore the company's failure with those after to see if there's a statistically significant difference between...
Confidence intervals are conducted using statistical methods, such as a t-test. A t-test is a type of inferential statistic used to determine if there is a significant difference between the means of two groups, which may be related to certain features. Calculating a t-test requires three key...
reflecting changing economic conditions and policy approaches. The magnitude of rate changes can vary. While 25 basis point adjustments are standard, the Fed may opt for more significant changes (such as 50 basis points or more) if it believes more dramatic action is needed to influence economic...