1. Un grupo de estudiantes está investigando la calidad del agua en el Rio Cauca cerca de una planta industrial. El limite máximo aceptable para la concentración de plomo en el agua según las normas ambientales es de \( 0.015 \mathrm{mg} / \mathrm{L} \). Después de realizar un muestreo, obtienen una muestra con una media de concentración de plomo de \( 0.018 \mathrm{mg} / \mathrm{L} \) y una desviación estándar de \( 0.004 \mathrm{mg} / \mathrm{L} \). El tarnaño de la muestra es de 40 . ¿La concentración media de plomo en el rio excede el limite aceptable? Nivel de significancia: 0.05

\#7 A set of data has correlation coefficient \( r \). For which value of \( r \) would the average magnitude of the residuals be the smallest? a. \( r=-0.034 \) b. \( r=0.472 \) c. \( r=0.908 \) d. \( r=0.952 \)

For the given data: 22; \( 9 ; 19 ; 2 ; 38 ; 40 ; 7 ; 38 ; 44 ; 6 ; 12 ; 10 ; 20 ; 31 ; 48 ; 45 \) Determine the Quartiles, Q1, Q2 and Q3 of the data: Q1: Q2:

\#3 A set of data has correlation coefficient \( r \). For which value of \( r \) would the average magnitude of the residuals be the largest? a. \( r=-0.516 \) b. \( r=-0.445 \) c. \( r=0.875 \) d. \( r=0.158 \)

3 Get a similar questlon You can retry this question below A sample of size \( n=10 \) is drawn from a population. The data is shown below. \( \begin{array}{lllll}102.8 & 115.4 & 98.2 & 96.2 & 93.3 \\ 115.4 & 81.8 & 76.1 & 115.4 & 88.9\end{array} \) What is the range of this data set? range \( =\begin{array}{ll}39.3\end{array} \) What is the standard deviation of this data set? (Round to 2 decimal places) stdev \( =16.03 \)

\#2 A survey was taken comparing the number of hours per week students spent studying and their performance on an exam. If a linear regression was performed and the correlation coefficient was -0.017 , what can be said about these results? a. As the number of hours spent studying increases, student exam performances will likely not change. b. As the number of hours spent studying inrceases, student exam performances will probably increase. c. As the number of hours spent studying increases, student exam performances will probably decrease. d. There is little evidence of a linear relationship between the number of hours spent studying and student exam performances.