Encontrar la Esperanza Matemática y Desviación Estándar del número de imperfecciones (y) en pizarra acrílica. (2 puntos) y 0 1 2 3 P(y) 1/8 ¼ ½ 1/8

Responder:

1,625; 0.8569

Explicación paso a paso:

y ___0 1 2 3

P (y) _1 / 8 ___ ¼ ___ ½ 1/8

Valor esperado (E (x)): Σx * p (x)

= (0 * (1/8)) + (1 * (1/4)) + (2 * (1/2)) + (3 * (1/8)) = 1,625

La desviación estándar = sqrt (Var (x))

Var (X) = Σx²p (x) * E (x) ²

Var (X) = [(0 ^ 2 * (1/8)) + (1 ^ 2 * (1/4)) + (2 ^ 2 * (1/2)) + (3 ^ 2 * (1 / 8))] - 1.625²

Var (X) = (0 * (1/8)) + (1 * (1/4)) + (4 * (1/2)) + (9 * (1/8)) - 1.625 ^ 2

= 3.375 - 2.640625

= 0,734375

Desviación estándar = Sqrt (0,734375) = 0,8569

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15