Americans receive an average of 15 Christmas cards each year. Suppose the number of Christmas cards is normally distributed with a standard deviation of 5 . Let X be the number of Christmas cards received by a randomly selected American. Round all answers to 4 decimal places where possible. a. What is the distribution of X ? \( \mathrm{X} \sim \mathrm{N}(15 \) b. If an American is randomly chosen, find the probability that this American will receive no more than 17 Christmas cards this year. c. If an American is randomly chosen, find the probability that this American will receive between 17 and 23 Christmas cards this year. d. \( 85 \% \) of all Americans receive at most how many Christmas cards? (Please enter a whole number)

Exercice A Soit la suite \( \left(u_{n}\right) \) définie par \( u_{0}=1 \) et pour tout entier \( n, u_{n+1}=\frac{2 u_{n}}{2+3 u_{n}} \). (1) Calculer les termes \( u_{1} \) et \( u_{2} \). (2) La suite \( \left(u_{n}\right) \) est-elle arithmétique ? géométrique ? (3) On admet que, pour tout \( n, u_{n} \) n'est pas nul. On pose \( v_{n}=1+\frac{2}{u_{n}} \). a) Calculer les trois premiers termes de \( \left(v_{n}\right) \). b) Déterminer la nature de \( \left(v_{n}\right) \). c) Exprimer \( v_{n} \) en fonction de \( n \). En déduire \( u_{n} \) en fonction de \( n \).

Loe las situaclonos y respondo las preguntas. 15) Si 6 kg do carno cuostan \( \$ 48.000 \), ccuánto cuestan 9 kg do carno? \( \begin{array}{lll}\text { A) } \$ 68.000 & \text { B) } \$ 72.000 & \text { C) } \$ 78.000 \\ (85,72) & (52,65) & (32,27)\end{array} \)

1. Вычислите значение выражения: а) \( \left(-\frac{2}{3}\right)^{3}+\frac{2^{3}}{3}-\frac{2}{(-3)^{3}} \); б) \( 5^{2}-(-3)^{2}-(-1)^{0} \).

4 a) \( x=24 ; y= \)

art 3 of 6