In a chi-square test for independence, the null hypotesis is that ?

In how many ways can 7 graduate students be assigned to 1 triple and 2 double hotel rooms during a conference

Solve the following problems applying Polya’s Four-Step Problem-Solving strategy.
If six people greet each other at a meeting by shaking hands with one another, how many handshakes take place?

Alfred missed a class test. For the test that Alfred missed, the class mean was 18 and the standard deviation was 4. If his teacher is going to give Alfred a mark based on his standard score, what mark should Alfred receive?

Out of a 54 person sample from our fall Math-150 classes, ${\displaystyle 12.4\mathrm{\%}}$ of the students are left-handed. Using a TI 84 graphing calculator:
Construct an ${\displaystyle 80\mathrm{\%}}$ confidence interval for the population proportion, p. Round to tenths of a percent and write a sentence answer.
The U.S. has ${\displaystyle 13.1\mathrm{\%}}$ of it’s population that are left-handed. Did this fall in your confidence interval from part a?
Be sure to show all calculator commans used.

Let the continuous random variables X and Y have joint pdf

$f(x,y)=e^{-x-y},0$

a)$e^{-y}$

b)$e^{-x}$

c)$\frac{e^y}{e^{-x}}$

Why are measures of central tendency essential to descriptive statistics?

Find the critical value z a/2 that corresponds to a ${\displaystyle 93\mathrm{\%}}$ confidence level