Fill in the following blank so that the resulting statement is true. The formula \( \sqrt{\frac{\sum(\text { data item-mean })^{2}}{n-1}} \) gives the value of the for a data set.

If the number 31 is added to the data set \( 3,5,6,6,8,11,12,22,26 \), by what value will the average of the data set increase?

Suppose the mean IQ score of people in a certain country is 100 . Suppose the director of a college obtains a simple random sample of 42 students from that country and finds the mean IQ is 103.6 with a standard deviation of 13.5 . Complete parts (a) through (d) below. (a) Consider the hypotheses \( \mathrm{H}_{0}: \mu=100 \) versus \( \mathrm{H}_{1}: \mu>100 \). Explain what the director is testing. Perform the test at the \( \alpha=0.01 \) level of significance. Write a conclusion for the test. Explain what the director is testing. Choose the correct answer below. A. The director is testing if the sample provided sufficient evidence that the population mean IQ score is actually greater than 100 . C. The director is testing if the sample provided sufficient evidence that the population mean IQ score is actually equal to 100 . D. The director is testing if the sample provided sufficient evidence that the population mean IQ score is actually not equal to 100 . Find the test statistic for this hypothesis test. \( \square \) (Round to two decimal places as needed.)

I. Se refieren a indicadores de posición que dividen en cuatro partes porcentuales iguales una distribución de datos ordenados. II. El segundo cuartil corresponde a la mediana de la distribución de datos. III. El tercer cuartil indica el valor mínimo que toma el \( 75 \% \) de la distribución ordena de datos. IV. El cuartil uno es equivalente al decil 2 . De las anteriores afirmaciones cuál o cuáles son verdaderas: Seleccione una: I y IV II I y II II y III.

(c) Consider the hypotheses \( \mathrm{H}_{0}: \mu=104 \) versus \( \mathrm{H}_{1}: \mu>104 \). Explain what the director is testing. Perform the test at the \( \alpha=0.01 \) level of significance. Write a Explain what the director is testing. Choose the correct answer below. A. The director is testing if the sample provided sufficient evidence that the population mean lQ score is actually not greater than 104 . The director is testing if the sample provided sufficient evidence that the population mean lQ score is actually greater than 104. C. The director is testing if the sample provided sufficient evidence that the population mean IQ score is actually not equal to 104 . D. The director is testing if the sample provided sufficient evidence that the population mean IQ score is actually equal to 104. Find the test statistic for this hypothesis test. 0.83 (Round to two decimal places as needed.) Find the P-value for this hypothesis test. \( \square \) (Round to three decimal places as needed.)

If the number 31 is added to the data set \( 3,5,6,6,8,11,12,22,26 \), by what value will the average of the data set increase?