5. En una muestra al azar de 600 mujeres, 300 indican que están a favor de los bonos estudiantiles. Determinar un intervalo de confianza del \( 90 \% \) para la proporción de mujeres que favorecen esta ayuda.

Coffee consumption has been found to be negatively correlated with amount of sleep, with a correlation coefficient of 0.5 . How much can the coffee consumption account for the variance of amount of sleep? \( 0.5 \% \) \( 50 \% \) \( 0.25 \% \) \( 25 \% \)

\begin{tabular}{l} In a re-analysis of published studies, Twenge and Im (2007) found that for the \\ time period 1958-2001, the need for social approval of people in the United \\ States was negatively correlated with the U.S. divorce rate during the same \\ period (the correlation coefficient was -0.38). This correlation means that _- \\ divorce rates were high when the need for social approval was high \\ the need for social approval spurred people to divorce \\ the need for social approval prevented people from seeking divorce \\ divorce rates were low when the need for social approval was high \\ \hline\end{tabular}

Which of these values of the correlation coefficient indicates the weakest relationship between two variables? -0.30 -0.18 0.03 0.42

8. For a class project, a political science student at a large university wants to estimate the percent of students who are registered voters. She surveyed 190 students and finds that 80 are registered voters. Compute a \( 98 \% \) confidence interval for the true percent of students who are registered voters and interpret the confidence interval. (Round the answers to 4 decimal places.)

Researchers who study the process of reading in children have discovered that better readers watch fewer hours of television. If a scatterplot of the data is drawn, the points on the graph would likely run from ___ left to right. upper; lower upper; upper lower; upper lower; lower