mechanic #1's rate = x
mechanic #2's rate = y
* Their rate is dollars per hour ($/hr)
mechanic #1 worked for 20 hours (hr × $/hr = $)
20x = money earned by mech#1
and mechanic #2 worked for 5 hours
5y = money earned by mech#2
together they charged a total of $1150. So the amount of money earned by both mechanics.
20x + 5y = 1150
the sum of the two rates was $95 per hour.
x + y = 95
which means
x = 95 - y
plug (95 - y) in for "x" in the other equation to get everything in terms of one variable.
20(95 - y) + 5y = 1150
solve for y
1900 - 20y + 5y = 1150
1900 - 15y = 1150
-15y = 1150 - 1900
-15y = -750
y = -750/-15
y = 50 $/hr
Now use this to solve for x
x + y = 95
x + 50 = 95
x = 95 - 50
x = 45 $/hr
mech#1 charged 45$/hr
mech #2 charged 50$/hr
Answer:
{58.02007 , 61.97993]
Step-by-step explanation:
Data are given in the question
Sample of cars = n = 121
Average speed = sample mean = 60
Standard deviation = sd = 11
And we assume
95% confidence t-score = 1.97993
Therefore
Confidence interval is
![= [60 - \frac{1.97993 \times 11}{\sqrt{121} }] , [60 + \frac{1.97993 \times 11}{\sqrt{121} }]](https://tex.z-dn.net/?f=%3D%20%5B60%20-%20%20%5Cfrac%7B1.97993%20%5Ctimes%2011%7D%7B%5Csqrt%7B121%7D%20%7D%5D%20%2C%20%20%5B60%20%2B%20%20%5Cfrac%7B1.97993%20%5Ctimes%2011%7D%7B%5Csqrt%7B121%7D%20%7D%5D)
= {58.02007 , 61.97993]
Basically we applied the above formula to determine the confidence interval
Knowing that one dime has a 10 cent value and that a nickle has a 5 cent value, we can use multiplication or addition to find the answer.
5 x 10 = 50 5 dimes together are worth 50 cents.
2 x 5 = 10 2 nickles together are worth 10 cents.
50 + 10 = 60 5 dimes and 2 nickles are worth 60 cents when added together.
ANSWER: Aaron has 60 cents.
Answer:
Constants thats what it is hope this helps :)
Step-by-step explanation:
