3. Describing Data Numerically

As the mean $\mu$ increases in a normal distribution, what happens to the graph of the normal curve?

Which formula should you use to calculate the variance and which formula should you use to calculate the standard deviation of a sample of $n$ observations $x_1$, $x_2$, ..., $x_n$?

Which of the following is true about $\mathrm{variance}$?

Which of the following best describes the relationship between $\mathrm{variance}$ and $\mathrm{standard\; deviation}$ for a data set?

Which three quantities are required to calculate the variance of a data set?

Which of the following is the correct formula for the population variance?

If a set of data has a standard deviation of $0$, which of the following must be true about the data?

If an observation has a z-score of $0$, which of the following is true?

In a normal distribution, which of the following statements is true regarding the $\mathrm{mean}$ and the $\mathrm{median}$?

$Which\; characteristic\; of\; data\; is\; a\; measure\; of\; the\; amount\; that\; the\; data\; values\; vary?$

Given the sample data set: $2$, what is the standard deviation of this sample?

If the standard deviation for a sample is $s=9$, what is the variance of the sample?

A sample of $n=15$ scores has a mean of $m=20$ and a sample variance of $s^2=9$. What is the sample standard deviation?