Let X be the number of adults correctly interpret a scatterplot and n be the sample number of adults.
From the given information, X=2065 and n=3278.
The given claim is that more than 60% of Americans are able to correctly interpret scatterplots.
State the hypotheses.
That is, the proportion of Americans are able to correctly interpret is not more than 0.60.
That is, the proportion of Americans are able to correctly interpret is more than 0.60.
The sample proportion is
then,the test statistic is
The p value is obtained by using EXCEL
Thus the p value is 0.0002
If the P-value is less than or equal to 0.05, then reject the null hypothesis.
Here, the P-value is 0.0002.
This is less than 0.05.
By the rejection rule, reject the null hypothesis.
Thus, there is good evidence that more than 60% of Americans are able to correctly interpret scatterplots.
Unusual points Each of the four scatterplots that follow shows a cluster of points and one “stray” point. For each, answer these questions:
1) In what way is the point unusual? Does it have high leverage, a large residual, or both?
2) Do you think that point is an influential point?
3) If that point were removed, would the correlation be- come stronger or weaker? Explain.
4) If that point were removed, would the slope of the re- gression line increase or decrease? Explain
Construct a scatterplot and identify the mathematical model that best fits the given data.
Make a scatterplot of the data. Use 87 for 1987