Answer:
Step-by-step explanation:
If we let x = the amount of 5% solution and y = the amount of pure alcohol, we can set up that
.05x+y is the amount of alcohol in our resulting mixture, and x+y is the total amount in our resulting mixture (which we know is 380)
so we also know that:
(.05x+y)/380 = .6
If we simplify this we come up with:
.05x+y=228
and we know x+y=380
If we solve this as a system of equations, we will find that:
x=160 ml
y=220 ml
Answer:
x=11 degrees
Step-by-step explanation:
45+4x+1=90
46+4x=90
4x=44
x=11
$9 per hour for 14 hours the first week can be found by doing 9 • 14, which equals 126.
In the first week, Erika earned $126.
$9 per hour for 20 hours for the second week can be found by doing 9 • 20, which equals 180.
In the second week, Erika earned $180.
To find the total amount Erika earned in both weeks, add how much she made in week 1 to how much she made in week 2.
126 + 180 = 306
Erika made $306 during these 2 weeks.
If i understand the question correctly then the answer you are looking for is 9
As described in z-distribution the answers are given below:
a) The 95% confidence interval estimate for the population mean spending by a customer on visiting salon per month is given as follows: (747, 853).
b) The sampling error at 95% confidence level is of: $35.78.
What is a z-distribution ?
The normal distribution with a mean of 0 and a standard deviation of 1 is referred to as the standard normal distribution (also known as the Z distribution) (the green curves in the plots to the right). It is frequently referred to as the bell curve since the probability density graph resembles a bell.
solution:
The bounds of the confidence interval are given as follows:
In which:
is the sample mean.
z is the critical value.
n is the sample size. is the standard deviation for the population.
The parameters for this problem are given as follows:
Hence the lower bound of the interval is of:
800 - 200 x 1.96/square root of 55 = 747.
The upper bound of the interval is of:
800 + 200 x 1.96/square root of 55 = 853.
The sampling error for a sample size of 120 is calculated as follows:
200 x 1.96/square root of 120 = $35.78.
To learn more about the z-distribution from the given link
brainly.com/question/4079902
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