FAQs

What this page covers

This page gathers the questions that apply to the whole workshop. Each calculator also ends with five questions about its own formula. If you came for a specific test, interval, or payment, open that page. The answers there use the numbers from its worked example. The answers here explain how the site is built and how to read it.

People ask whether the tools are free. They are. There is no trial, no account, and no payment step before a result. If advertising is added later, it will sit around the writing, not inside the arithmetic, and the privacy policy will describe the cookies. The calculation will still run on the page you already loaded.

Choosing an average

People ask whether a result is stored. It is not stored by us. The script reads the fields in your browser and writes the ticket underneath. Close the tab and the numbers are gone. The contact form is different, and only because you chose to send a message. Search suggestions load a list of titles. They do not include values you typed into a form.

People ask which average to use. Use the mean when every unit of size should pull. Use the median when a long tail would distort that story and you want the middle of the ordered list. Use the mode when the most common category is the decision. Use a weighted mean when the rows represent different numbers of people. Use the trimmed option on the average page only when you have already decided that the single highest and lowest values should step out, and say that you did.

Phones, access, and long pages

People ask why some famous names are split across pages. A z test with known sigma is a different claim from a t test. A paired design is a different claim from two independent samples. A p-value from a published r is a different worksheet from a correlation computed on raw pairs. Splitting them keeps the steps short enough to check and keeps the title honest.

People ask about phones. The layout collapses to one column, the menu becomes a button, and the same scripts run. You should not have to pinch sideways to reach a field. If a page does scroll, it is because the explanation is long, not because a banner is pushing the form away. Top and Bottom buttons sit at the corner so you can leave a long essay without hunting.

People ask whether health pages are safe to follow alone. They are not a care plan. Read the disclaimer. Use insulin, pregnancy, dosing, and alcohol pages only as labelled arithmetic, and take the personal decision to a clinician or, for driving, simply do not drive after drinking. Pet doses start from a veterinarian's milligrams per kilogram, not from a dropdown of drug names.

Bugs, health limits, and maps

People ask how to report a bug. Use the contact page, include the URL, and include inputs that are not sensitive. Tell us the browser if the ticket did not update. A wrong result with the example still loaded is the most useful report we can receive, because we can compare it with the anchor values used when the page was built.

People ask about accessibility. Pages use one h1, labelled fields, a skip link, and visible focus. The result ticket announces itself to assistive technology as a live region. Charts are accompanied by the same numbers in text. Colour is not the only signal that a result exists. If a control cannot be reached by keyboard, that is a bug and the contact page is the right place to describe the browser and the page.

People ask about the Top and Bottom buttons. They move the window to the start or the end of the current document. They are not a second menu. On a long method page they save a hunt through a scrollbar. If your system asks for reduced motion, the jump is instant rather than animated. The same preference turns off the small entrance motion on cards. People also ask whether the site works without a mouse. It does. Tab to the skip link, then to the menu, the search box, the fields, and the questions. Buttons are real buttons. Links are real links. A chart is extra. The numbers it draws are also written out. The length of a method page is the definition, the example, the second example, and the mistakes. The form sits above that essay. You can calculate and leave. The essay is there for the moment you need to know whether the number deserved to be calculated at all. If a page still feels long after that, use the contents links. They jump. They do not add a second essay.

People ask whether the sitemaps are the same as the HTML index. They are not. The HTML index is for readers. The XML sitemaps are for crawlers and split pages, calculators, and blogs so indexing stays clean. People also ask why Guides is not in the menu. The journal is labelled Blogs on purpose, matching the URL and the date stamp on every essay.