1.the 2d chart is the best chose
try your best i dont understand it propely
Answer:
Quarters = 10
Dimes = 15
Step-by-step explanation:
d = number of dimes, q = number of quarters
d + q = 25 is the equation for number of coins
0.1d + 0.25q = 4 is the equation for value of coins
First, solve for d in terms of q:
d + q = 25
d = 25 - q
Then substitute that into the other equation:
0.1(25 - q) + 0.25q = 4
2.5 - 0.1q + 0.25q = 4
0.15q = 1.5
q = 10
And back to d = 25 - q, d = 25 - 10 = 15
Check the math:
0.1(15) + 10(0.25) = 1.5 + 2.5 = 4
LMK if you have questions
Answer:
a) 
b) n = 381
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
The margin of error is:
90% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
a. Assume that nothing is known about the percentage of computers with new operating systems. n = ?
When we do not know the proportion, we use 
, which is when we are going to need the largest sample size.
The sample size is n when M = 0.01.
b. Assume that a recent survey suggests that 99% of computers use a new operating system. n = ?
Now we have that 
. So
Rouding up
n = 381
Answer:
1. a=3
2. a=3
3. a=9
Step-by-step explanation:
1. 9/a+9-4=12-56/8+3
We move all terms to the left:
9/a+9-4-(12-56/8+3)=0
Domain of the equation: a=0
a∈R
We add all the numbers together, and all the variables
9/a+9-4-8=0
We add all the numbers together, and all the variables
9/a-3=0
We multiply all the terms by the denominator
-3*a+9=0
We add all the numbers together, and all the variables
-3a+9=0
We move all terms containing a to the left, all other terms to the right
-3a=-9
a=-9/-3
a=+3
