If two variables x and y are perfectly positively correlated then in the scatter diagram every point (x, y) lies o

The text seems to be incomplete, but based on what you've provided, if two variables x and y are perfectly positively correlated, then in the scatter diagram every point (x, y) lies on a straight line that slopes upward.

Here are the steps to understand this:

1. Correlation: Correlation is a statistical measure that describes the association between random variables. In this case, we are talking about a perfect positive correlation.

2. Perfect Positive Correlation: A perfect positive correlation means that for every increase in one variable, there is a corresponding increase in the other variable. The correlation coefficient in this case is +1.

3. Scatter Diagram: A scatter diagram (or scatter plot) is a two-dimensional graphical representation of a set of data. Each point on the plot represents the values of two variables.

4. In a scatter diagram, if every point (x, y) lies on a straight line that slopes upward, it means that there is a perfect positive correlation between the variables x and y. This is because as x increases, y also increases at a consistent rate.

So, to summarize, if two variables x and y are perfectly positively correlated, then in the scatter diagram every point (x, y) lies on a straight line that slopes upward. This is because as the value of x increases, the value of y also increases at a consistent rate.