The owner of a local phone store wanted to determine how much customers are willing to spend on the purchase of a new phone. In a random sample of 14 phones purchased that day, the sample mean was $492.678 and the standard deviation was $26.4871. Calculate a 99% confidence interval to estimate the average price customers are willing to pay per phone.

99% confidence interval bto estimate the average price customers are willing to pay per phone is between a lower limit of $471.356 and an upper limit of $514.

Step-by-step explanation:

Confidence interval = mean + or - Error margin (E)

mean = $492.678

sd = $26.4871

n = 14

degree of freedom = n - 1 = 14 - 1 = 13

confidence level = 99%

t-value corresponding to 13 degrees of freedom and 99% confidence level is 3.012

E = t×sd/√n = 3.012 × $26.4871/√14 = $21.322

Lower limit = mean - E = $492.678 - $21.322 = $471.356

Upper limit = mean + E = $492.678 + $21.322 = $514

99% confidence interval to estimate the average price customers are willing to pay per phone is between $471.356 and $514.

la parábola es el lugar

geométrico en el cual los puntos tienen una distancia idéntica, equidistantes,

de un punto denominado foco, f, y una recta denominada directriz

el radio vector de una

parábola es el segmento que existe entre un punto cualquiera y el foco.

por la ecuación se observa

que la parábola abre hacia la derecha, por lo cual podemos usar las siguientes fórmulas

la ecuación ordinaria de la

parábola es y^2 = 4px, donde p es la longitud desde el vértice de la parábola al

foco.

la fórmula de la directriz

es x + p = 0

resolviendo:

y^2-9x = 0

y^2 = 9x

4p = 9, entonces p = 9/4

entonces el foco tendrá la

coordenada f(9/4,0)

la directriz vendrá

expresada por

x + p = 0

x = -p

x = -9/4

el problema indica que la

ordenada es igual a 6, entonces

(6)^2=9x

x = 36/9

x = 4

entonces el punto al cual

hay que obtener la distancia será p(4,6)

calculando se tendrá: pf = 

pf = 6,25 u

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step-by-step explanation:

many reason,

step-by-step explanation: