AP statistics chapter 20 by Stats modelling the world third edition by David E. Bock

● Null hypothesis - The claim being assessed in a hypothesis test is called the null
hypothesis. Usually, the null hypothesis is a statement of “no change from the
traditional value,” “no effect,” “no difference,” or “no relationship.” For a claim to be
a testable null hypothesis, it must specify a value for some population parameter
that can form the basis for assuming a sampling distribution for a test statistic.
● Alternative hypothesis - The alternative hypothesis proposes what we should
conclude if we find the null hypothesis to be unlikely.
● Two-sided alternative - An alternative hypothesis is two-sided when we are
interested in deviations in (Two-tailed alternative) either direction away from the
hypothesized parameter value.
● One-sided alternative - An alternative hypothesis is one-sided (e.g., ) when we are
interested (One-tailed alternative) in deviations in only one direction away from
the hypothesized parameter value.
● P-value - The probability of observing a value for a test statistic at least as far
from the hypothesized value as the statistic value actually observed if the null
hypothesis is true. A small P-value indicates either that the observation is
improbable or that the probability calculation was based on incorrect

assumptions. The assumed truth of the null hypothesis is the assumption under
suspicion.
● One-proportion z-test - A test of the null hypothesis that the proportion of a single
sample equals a specified value.