The grades on the second statistics test for Mr. Brown's class are in the following list. Find the frequency distribution for the grades. \[ \text { Answer } \] Grade C frequency

Find the standard deviation of \( x \), given that \( \Sigma 4 x^{2}=14600, \Sigma 2 x=420 \) and \( n=20 \).

5 The distribution of resting pulse rates of a sample of 2000 20-year-old men is approximately normal, with a mean of 66 beats/minute and a standard deviation of 4 beats/minute. a What percentage of these men have pulse rates of: i higher than 66 ? ii between 66 and 70 ? iii between 62 and 74 ? b Approximately how many of this sample of 2000 men have pulse rates between 54 and 78 beats/minute?

Which of the following is/are part of descriptive statistics? central tendency. variability. linear regression. correlation. all of the above.

Classifying subjects on the basis of gender is an example of what kind of measurement scale? nominal. ordinal. interval. discrete. continuous.

Cite as características que um bom diagrama de dispersão deve ter para facilitar a interpretação dos dados.