To start out the equation you know that they both spent the same. The right of the equal sign is what Tanya spent and to the left was what Tony spent.
3x = 4(x-2.25)
If you solve it you get x = $9
Now that is what the cost was for each item that Tanya bought. The number in parenthesis() is what Tony spent on each item.
Plug in 9 to x in (x-2.25)
You should get $6.75 for the amount of each item Tony spent.
The expression is Irrational
Because one of the terms is irrational
your basically going to add them to see the difference 1,281+282= 1,363
<h3>
Answer: 8.323 (approximate)</h3>
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Explanation:
s = 32 = sample standard deviation
n = 40 = sample size
Despite not knowing the population standard deviation (sigma), we can still use the Z distribution because n > 30. When n is this large, the student T distribution is approximately the same (more or less) compared to the standard Z distribution. The Z distribution is nicer to work with.
At 90% confidence, the z critical value is roughly z = 1.645. This can be found using either a Z table or a calculator.
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We have these values:
- z = 1.645 (approximate)
- s = 32
- n = 40
Plug these values into the margin of error formula.
The margin of error is roughly 8.323
I rounded to 3 decimal places because z = 1.645 is rounded to 3 decimal places. If your teacher wants some other level of precision, then be sure to follow those instructions.