To determine which window cleaner is most effective, Thad washes half of the windows in his house with one brand and the other half with a different brand. He then compares the results to draw a conclusion about which cleaner is most effective. What kind of statistical study did Thad conduct? A. observational study B. experiment C. survey D. theoretical study

63. Sea \( \mathbf{p} \) la desviación estándar de los 5 primeros números primos. Si se resta 1 , a cada uno de estos números, entonces la varianza del nuevo conjunto de números es A) \( p-5 \) B) \( 5-p \) C) \( (p-5)^{2} \) D) \( p^{2} \) E) \( p^{2}-5 \)

To determine which window cleaner is most effective, Thad washes half of the windows in his house with one brand and the other half with a different brand. He then compares the results to draw a conclusion about which cleaner is most effective. What kind of statistical study did Thad conduct? A. observational study B. experiment C. survey D. theoretical study

700) Debido a los malos resultados de la prueba de Matemática el profesor decide subir las notas en dos décimas. ¿Cuál de los siguientes estadígrafos no cambia? I) Media II) Rango III) Varianza A) Solo I B) Solo II C) Solo III D) Solo II y III E) I, II y III

Select the correct answer. A local grocery store decides to offer a free piece of fresh fruit (banana or apple) to all shoppers in the produce department. The store is conducting an observational study to determine which type of fruit is selected more often. At the end of the first day, the store found that twice as many shoppers select an apple. The grocery store then repeats the observational study for 14 days. All studies yield similar results. What generalization can be made from the results of this study? A. Given the choice of any type of fruit, twice as many shoppers will select an apple. C. Given the choice of a banana or an apple, twice as many shoppers will select an apple. D. The results are inconclusive; therefore, a generalization cannot be made regarding which type of fruit is preferred by most shoppers.

703) Si se consideran dos muestras, en una de ellas el peso promedio de un mamut adulto se estimaba en 7.500 kg, y en la otra, el peso promedio de un ratón es de 30 gramos, con una desviación estándar de 5 gramos. De acuerdo con estos datos, se puede determinar que: A) Ambas muestras tiene igual dispersión B) La muestra de los mamuts es más homogénea que la de los ratones C) La muestra de los ratones es más homogénea que la de los mamuts. D) Una muestra para el peso de los mamuts siempre tendrá mayor dispersión que una E) muestra para el peso de los ratones.