Suppose the correlation coefficient between a baby's weight and the number of coffee shops in Plumville is 0.87 . Which statement must be true? A. As the baby gains weight, the number of coffee shops tends to increase. B. Having more coffee shops around causes the baby to gain weight. C. As the baby gains weight, the number of coffee shops tends to decrease.

1. La media y los que de los pesos de 500 estudiantes de un colegio es 70 kg y la desviación típica 3 kg . Suponiendo que los pesos se distribuyen normalmente, hallar cuántos estudiantes pesan: a) Entre 60 kg y 75 kg . b) Más de 90 Kg . c) Menos de 64 kg .

\( 1 \leftarrow \quad \begin{array}{l}\text { A sample of } 100 \text { randomly selected registered voters in a city was asked their political affiliation: Democrat (D), } \\ \text { Republican }(R) \text {, or Independent (I). The results of the survey are available below. Complete parts (a) through (e) } \\ \text { below. }\end{array} \)

Variance of 1,3,5,7,9.

Sea \( X \) una variable aleatoria con \( N(10,5) \), para que valor de \( x \) se cumple la siguiente probabilidad. \( P(X<x)=0.975 \)

La duración en horas de cierta marca de bombillos se ajusta a una distribución N(48000, 3000), La duraciōn de los bombillos en un intervalo de confianza del \( 80 \% \) está: