Answer:
q = 108-n
Step-by-step explanation:
Given: 108 coins containing only quarters and nickels
q = 108-n
since total number of coins is 108, and n= number of nickels
If you want to know how many of each kind of coin, read on:
First solve the number of quarters and nickels.
If all 108 coins are quarters, the value is 108*0.25 = $27
Since this value exceed the actual by 27-21 = $6,
we replace a number of quarters by nickels.
Each replacement will reduce the value by 25 - 5 = 20 cents = 0.2 dollars.
So it will take 6/0.2 = 30 replacements.
Therefore there are 108-35 = 78 quarters and 30 nickels.
Answer:
The confidence interval for the difference in proportions is
No. As the 95% CI include both negative and positive values, no proportion is significantly different from the other to conclude there is a difference between them.
Step-by-step explanation:
We have to construct a confidence interval for the difference of proportions.
The difference in the sample proportions is:
The estimated standard error is:
The z-value for a 95% confidence interval is z=1.96.
Then, the lower and upper bounds are:
The confidence interval for the difference in proportions is
<em>Can it be concluded that there is a difference in the proportion of drivers who wear a seat belt at all times based on age group?</em>
No. It can not be concluded that there is a difference in the proportion of drivers who wear a seat belt at all times based on age group, as the confidence interval include both positive and negative values.
This means that we are not confident that the actual difference of proportions is positive or negative. No proportion is significantly different from the other to conclude there is a difference.
We will use substitution to solve this system of linear equations, as the first equation has x and y with no coefficients, which makes it easier to find one in terms of the other. We can then substitute that value in the other equation and find the values of x and y.
x = y + 5 ---> equation 1
3x + 2y = 5 ---> equation 2
From equation 1, we get the value of x as y + 5. Using the substitution method, we can find the value of y by substituting (y+5) for x in the 2nd equation.
3(y+5) + 2y = 5
3y + 15 + 2y = 5
5y = 5 - 15
5y = -10
y = -2
Subsituting this value of y in (y+5), we can find x.
x = y + 5
x = -2 + 5
x = 3
Therefore, x = 3 and y = -2.
I will also solve this using elimination method.
Let us multiply equation 1 by 2, so that we get 2y in both equations.
2x = 2y + 10
3x + 2y = 5
Let us add both the equations.
2x + 3x + 2y = 5 + 2y + 10
5x = 15 + 2y - 2y
5x = 15
x = 3
Substituting this value of x in equation 1, we get
x = y + 5
3 = y + 5
y = 3 - 5
y = -2
Therefore, x = 3 and y = -2.
It is definitely D because on part 1 n=24n+20 and if n equals 0 than 24 (0) +20= 20 and that is true. on part 2 if n =0 than 24 (0)+ 20 (0-1)=20 than 20 (-1)=20 -20= 20. that statement is false because-20 does not equal 20. AND for part 3 n=1 and f (1-1) + 24= 44 so f (0) + 24 =44 and keep in mind f (0) equals 20 so 44=44 because 24+20 is 44. so that is a true statement too
