If a scatter plot shows points that are closely clustered together, what can you infer about the correlation between the variables?

On an examination the average grade was 74 and the standard deviation was 7 . If \( 10 \% \) of the class are given A's and the distribution of grades is to follow a normal distribution. Then the lowest possible A and highest possible B if z.10=1.28 is: \( \begin{array}{ll}\text { (a) } 83 \text { and } 82 & \text { (b) } 84 \text { and } 83 \\ \text { (c) } 85 \text { and } 84 & \text { (d) } 82 \text { and } 81\end{array} \)

Define un diagrama de dispersión y describe su propósito en la estadística.

What is a scatter plot?

If a set of observations is normally distributed, then the percentage of observations differs from mean by more than \( 1.3 \sigma \) is: \( \begin{array}{ll}\text { (a) } 19.36 \% & \text { (b) } 90.32 \% \\ \text { (c) } 9.68 \% & \text { (d) None of these }\end{array} \)

\( A \) is students who learn English. \( B \) is students who learn french. \( C \) is students who learn Khmer. \( n A \) is \( 18, n B \) is \( 18, n C \) is \( 26, n A n C \) is \( 13, n B n C \) is \( 11, n A n B n C \) is \( 6, n A u B u C \) is 35. How many students learn french and English?