Answer:
A. 9.7%
Step-by-step explanation:
margin of error:
z *
n is sample size
z is the z score (for a 95% confidence interval you would use 1.96)
p is the sample proportion
to solve for 'p', remember that if a decimal value is given, use that. but if it is a whole number, then divide that number by the sample size, and substitute it into the formula.
in this case we are given 43% so 0.43.
in the formula :
1.96 *
if you calculate this you get around 0.09703 this is 9.7%
Answer:
Step-by-step explanation:
Let x and y represent the cost of a cookie and a cupcake, respectively.
4x +3y = 13.25
5x +2y = 11.75 . . . . . . the system of equations
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By Cramer's rule:
x = (3(11.75) -2(13.25))/(3(5) -2(4)) = 8.75/7 = 1.25
y = (13.25(5) -11.75(4))/7 = 19.25/7 = 2.75
The cost of one cookie is $1.25; the cost of one cupcake is $2.75.
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Cramer's rule gives the solution to the system of equations ...
ax +by =c
dx +ey = f
as ...
∆ = bd -ea
x = (bf -ec)/∆
y = (cd -fa)/∆
