Answer:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the scores of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the normal standard table or excel and we got:
X=6y
sum of their reciprocals
(1/x)+(1/y)=7
x=6y
1/6y+1/y=7
1/6y+6/6y=7
7/6y=7
times both sides by 6y
7=42y
divide both sides by 42
1/6=y
x=6y
x=6(1/6)
x=6/6
x=1
the numbers are 1 and 1/6
Answer:
Altogether they lost 150 pennies.
Step-by-step explanation:
X = Dante's pennies
Y = Mia's pennies
X + Y = 350 1/2 X = 2/3 Y
X = 4/3 Y
4/3 Y + Y = 350
7/3 Y = 350
Y = 350 * 3/7
Y = 50 * 3
Y = 150
X + 150 = 350
X = 200
1/2 * 200 = 2/3 * 150
100 . = 100
1/2 * 200 = 100 -> Dante lost 100 pennies
1/3 * 150 = 50 -> Mia lost 50 pennies
Altogether they lost 150 pennies.
W=3L
W+W+L+L=72
Replace W with 3L: 3L+3L+L+L=72
8L=72
L=9
W=27