Answer: true
Step-by-step explanation:
Z-tests are statistical calculations that can be used to compare the population mean to a sample mean The z-score is used to tellsbhow far in standard deviations a data point is from the mean of the data set. z-test compares a sample to a defined population and is typically used for dealing with problems relating to large samples (n > 30). Z-tests can also be used to test a hypothesis. Z-test is most useful when the standard deviation is known.
Like z-tests, t-tests are used to test a hypothesis, but a t-test asks whether a difference between the means of two groups is not likely to have occurred because of random chance. Usually, t-tests are used when dealing with problems with a small sample size (n < 30).
Both tests (z-tests and t-tests) are used in data with normal distribution (a sample data or population data that is evenly distributed around the mean).
An expression is just like an equation but without the equal sign.
Answer:
About 73 degrees
Step-by-step explanation:
By the law of cosines:

Hope this helps!
Answer:
80*
Step-by-step explanation:
The answer is c because it’s not a or d and maybe not b so ye c