Se procede a completar la pregunta para darle solución al cuestionamiento : a.
Mayor que 4.
B. Entre 4 y 6c.
Igual a 7Solucionando el planteamiento tenemos que : a.
Mayor que 4 = 0, 9453.
B. Entre 4 y 6 = 0, 2093.
C. Igual a 7 = 0, 9996◘Desarrollo : Empleamos la distribución normal estandarizada, esto es N(0, 1).
Entonces la variable X la denotamos por Z : Z = X - μ / σ donde : σ = desviaciónμ = mediaX = variable aleatoriaX≈N (μ = 8 ; σ = 2, 5)a) P(x>4) = 1 - P(Z \ frac{4 - 8}{2, 5})" alt = "P(X>4) = P(Z> \ frac{4 - 8}{2, 5})" align = "absmiddle" class = "latex - formula"><img src="https://tex.z-dn.net/?f=P%28X%3E4%29%3D%20P%28Z%3E-1%2C6%29" />4) = P(Z> - 1, 6)" alt = "P(X>4) = P(Z> - 1, 6)" align = "absmiddle" class = "latex - formula"><img src="https://tex.z-dn.net/?f=P%28X%3E4%29%3D%201-P%28Z%3C-1%2C6%29" />4) = 1 - P(Z" alt = "P(X>4) = 1 - P(Z" align = "absmiddle" class = "latex - formula"><img src="https://tex.z-dn.net/?f=P%28X%3E4%29%3D%201-0%2C0547" />4) = 1 - 0, 0547" alt = "P(X>4) = 1 - 0, 0547" align = "absmiddle" class = "latex - formula"><img src="https://tex.z-dn.net/?f=P%28X%3E4%29%3D%200%2C9453" />4) = 0, 9453" alt = "P(X>4) = 0, 9453" align = "absmiddle" class = "latex - formula">b) <img src="https://tex.z-dn.net/?f=P%284%3CX%3C6%29%3D%20P%28X%3C6%29-P%28X%3C4%29" /><img src="https://tex.z-dn.net/?f=P%284%3CX%3C6%29%3D%20P%28Z%3C%5Cfrac%7B6-8%7D%7B2%2C5%7D%29-P%28Z%3C%5Cfrac%7B4-8%7D%7B2%2C5%7D%29" /><img src="https://tex.z-dn.net/?f=P%284%3CX%3C6%29%3D%20P%28Z%3C2%2C8%29-P%28Z%3C0%2C8%29" /><img src="https://tex.z-dn.net/?f=P%284%3CX%3C6%29%3D0%2C9974-0%2C7881" /><img src="https://tex.z-dn.net/?f=P%284%3CX%3C6%29%3D0%2C2093" />c) P(X = 7)[img = 10][img = 11][img = 12].