Find the mean for the following group of data items. \( 7,1,5,4,6,3,1,9 \) The mean is T. (Type an integer or a decimal.)

QS-8 company that makes hair-care products had 7,000 people try a new shampoo. Of the 7,000 people, 14 had a mild allergir eaction. What percent of the people had a mild allergic reaction?

1) Observe o gráfico de setores ao lado: a) Calcule o ângulo central correspondente aos setore circulares de Futebol, Vôlei e Basquete. b) Se o ângulo central correspondente a "Outros" é igual a 18 quantos \% dos alunos responderam que preferem Natação? c) Se ao todo há 40 alunos no \( 7^{\circ} \) ano, calcule a quantidade de alunos por esporte: \( \frac{x+40}{00} \)

Twelve percent of your customers buy 4 desserts. How many desserts can you expect to sell to 500 people?

In a class, there are 750 learners in 1st year, 420 learners in 2 nd year. Draw a pie graph to represent the numbers of learners in these groups.

1. Estas interesado en detectar diferencias en tiempo promedio de programación de comerciales en horario estelar. Un estudio similar detecto una desviación estándar de 30 minutos. Quisieras calcular una muestra con una confiabilidad del \( 95 \% \) y un error máximo tolerable de 5 minutos en tus estimaciones. ¿Qué tan grande tiene que ser tu muestra?