Describing data, sampling, estimation, and inference. Mathematical probability belongs in Probability.
Test your knowledge with these top questions!
Which feature makes a soda taste test blind?
Brand reputations can shape expectations, so hiding labels helps separate the taste from the marketing.
On a scatter plot with age on the x-axis and height on the y-axis, what does a point farther right mean?
Two points directly above one another have the same age, even when their heights differ.
In a standard box plot, the box spans which portion of the ordered data?
The box leaves out the lowest and highest quarters, so extreme values do not set its length.
In a set of 20 numbers, what must grow if only the largest number is replaced by a much higher outlier?
The range uses only the smallest and largest values, so one extreme can make a tight cluster look widely spread.
In a fertilizer trial, which group provides a baseline for measuring the fertilizer's effect?
Plants can grow without fertilizer, so the control group helps separate normal growth from the fertilizer's effect.
Which sampling method gives every possible group of the chosen size an equal chance of selection?
A random-number generator can pick the sample from a numbered list, avoiding a researcher's personal choices.
When box plots use the same scale, what does a longer box indicate?
Two groups can have the same median yet different box lengths because typical values vary more in one group.
To test a diet's effect on memory, how should researchers handle sleep in the two study groups?
Sleep diaries can help researchers check whether participants actually followed the assigned sleep schedule.
Credit-card fraud systems use what method to flag purchases far outside a customer's usual spending pattern?
A genuine purchase can also break a spending pattern, so an automated alert calls for a closer check.
In a double-blind drug trial, which detail is hidden from participants and outcome assessors?
Trial teams may use coded medicine packages so staff can give treatments without knowing which medicine each package contains.