Inside Collection (Textbook): Collaborative Statistics (with edits: Teegarden)
Suppose you make an assumption about a property of the population (this assumption is the null hypothesis). Then you gather sample data randomly. If the sample has properties that would be very unlikely to occur if the assumption is true, then you would conclude that your assumption about the population is probably incorrect. (Remember that your assumption is just an assumption - it is not a fact and it may or may not be true. But your sample data are real and the data are showing you a fact that seems to contradict your assumption.)
For example, Didi and Ali are at a birthday party of a very wealthy friend. They hurry
to be first in line to grab a prize from a tall basket that they cannot see inside because
they will be blindfolded. There are 200 plastic bubbles in the basket and Didi and Ali
have been told that there is only one with a $100 bill. Didi is the first person to reach
into the basket and pull out a bubble. Her bubble contains a $100 bill. The
probability of this happening is
"Reviewer's Comments: 'I recommend this book. Overall, the chapters are very readable and the material presented is consistent and appropriate for the course. A wide range of exercises introduces […]"