$5.25, because if you multiply $6 by 7/8(fraction form), you get $5.25
Step-by-step explanation:
let necklace : x
let earrings : y
x+y=144 -1st eqn
6x+5y=825 -2nd eqn
y=144-X -3rd eqn
substitute eqn into 2nd eqn
6x+5(144-x)= 825
6x +720-5X =825 (expanded)
X = 825-720
X =105
substitute "X=105" into 1st eqn
(105)+y=144
y= 144-105
y=39
1 necklace = 105$
1 pair of earrings = 39$
(to check back: substitute the value into the original eqn)
Cancel something
we cancel x's
multiply 1st equation by 5 and 2nd by 7 and add them
-35x-30y=-5
<u>35x-28y=7 +</u>
0x-58y=2
-58y=2
divide both sides by -58
y=-1/29
sub back
5x-4(-1/29)=1
5x+4/29=1
minus 4/29 from both sides
note, 1=29/29
5x=25/29
divide bot sides by 5 (or times 1/5)
x=5/29
(5/29,-1/29)
Answer:
The upper limit of a 95% confidence interval for the population mean would equal 83.805.
Step-by-step explanation:
The standard deviation is the square root of the variance. Since the variance is 25, the sample's standard deviation is 5.
We have the sample standard deviation, not the population, so we use the t-distribution to solve this question.
T interval:
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 15 - 1 = 14
Now, we have to find a value of T, which is found looking at the t table, with 14 degrees of freedom(y-axis) and a confidence level of 0.95(
). So we have T = 1.761
The margin of error is:
M = T*s = 1.761*5 = 8.805.
The upper end of the interval is the sample mean added to M. So it is 75 + 8.805 = 83.805.
The upper limit of a 95% confidence interval for the population mean would equal 83.805.
No
3÷4 = .75
4÷5 = .8
5÷6 ≈ .8333
6÷7 ≈ .8571
These ratios are not the same.