Let's say x = hours washing cars and 13-x = hours walking dogs.
so 10*(x) + 9*(13-x) = 122, which is 10x + 9(13-x) = 122. that would be your system.
Answer:
Z=±1.65
Step-by-step explanation:
Some previous concepts
The p-value is the probability of obtaining the observed results of a test, assuming that the null hypothesis is correct.
A z-test for one mean "is a hypothesis test that attempts to make a claim about the population mean(μ)".
The null hypothesis attempts "to show that no variation exists between variables or that a single variable is no different than its mean"
The alternative hypothesis "is the hypothesis used in hypothesis testing that is contrary to the null hypothesis"
System of hypothesis
Null hypothesis: 
Alternative hypothesis: 
If the random variable is distributed like this: 
The significance level provided is
and the value of
.
Since we are conducting a bilateral test, then we have two critical values. We need to find two quantiles that accumulates 0.05 of the area on the tails of the normal standard distribution. And in order to find it we can use the following excel codes:
"=NORM.INV(0.05,0,1)" , "=NORM.INV(1-0.05,0,1)"
And we got this:
and 
So the correct answer for this case is:
Z=±1.65
The Acute Angles Of An Isosceles Triangle Never Add Up To 90°.
Determine the least three digit number that is divisible by 3,5, and 9
135
because 5 • 3 • 9 is 135 and there isn't a three digit number divisible by each of the three numbers
There are 2! = 2 ways to arrange the names of two basketball players in a hat.
Since, the are going to throw alphabetically, there is 1 way for the names to be arranged alphabetically.
Therefore, <span>the probability that they shoot free throws in alphabetical order is

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