Find an equation in standard form for the hyperbola with vertices at (0, +/- 9) and foci at (0, +/-10).

A. y^2/81 - x^2/100 = 1
B. y^2/81 - x^2/19 = 1
C. y^2/19 - x^2/81 = 1
D. y^2/100 - x^2/81 = 1

Find the standard form of the equation of the parabola with a focus at (0, -10) and a directrix at y = 10.
A. y = -1/10 x^2
B. y = -1/40 x^2
C. y^2 = -40x
D. y^2 = -10x

d. 24+-0.114

step-by-step explanation:

the question requires us to calculate the approximate 95% confidence interval for the mean number of ounces of ketchup per bottle in the sample given the following statistics;

sample mean = 24

standard deviation, σ = 0.4

sample size , n = 49

the confidence interval for a population mean is calculated using the formula;

sample mean ± z-score*(σ/sqrt(n))

the z-score associated with a 95% confidence interval, from the standard normal tables, is;

1.96

substituting these values into the formula;

24 ± 1.96*(0.4/7)

= 24 ± 0.112

from the alternatives given, choice d is closest to the above expression;

answer: you need to organize this better it does not make sense.

step-by-step explanation: ?

a28=58

step-by-step explanation:

a1=a1+(n-1)d

a28= 4+ (28-1)2

a28=4+(27)(2)

a28=4+54

a28=58