Answer:
x=5
y=4
Step-by-step explanation:
Step 1:
Let us solve for <em>x</em> using the equation by <u>isolating terms containing the variable</u>:
Great! <em>x</em> is 5... let's find <em>y</em>.
Step 2:
Since we know the value of <em>x</em>, we can use what we know to find <em>y</em> using the <u>other equation</u>:
<em>Given that x=5, we can </em><u><em>replace</em></u><em> x with 5</em>.
<em>I hope this helps! Let me know if you have any questions :)</em>
Answer:
a)From the central limit theorem we know that the distribution for the sample mean is given by:
And the standard error for the mean would be:
b) We want this probability:
And we can use the z score formula given by:
And replacing we got:
And we can find this probability with the complement rule and the normal standard deviation or excel and we got:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".
Solution to the problem
Part a
From the central limit theorem we know that the distribution for the sample mean is given by:
And the standard error for the mean would be:
Part b
We want this probability:
And we can use the z score formula given by:
And replacing we got:
And we can find this probability with the complement rule and the normal standard deviation or excel and we got:
Answer:
<em>Thus, the dimensions of the metal plate are 10 dm and 8 dm.</em>
Step-by-step explanation:
For a quadratic equation:
The sum of the roots is -b and the product is c. Note the leading coefficient is 1.
We know the perimeter of the rectangular metal plate is 36 dm and its area is 80 dm^2. Being L and W its dimensions, then:
P=2(L+W)=36
A=L.W=80
Note both formulas are closely related to the roots of the quadratic equation, we only need to adjust the data for the perimeter to be exactly the sum of L+W and not double of it.
Thus we use the semi perimeter instead as P/2=L+W=18
The quadratic equation is, then:
Factoring by finding two numbers that add up to 18 and have a product of 80:
The solutions to the equation are:
x=10, x=8
Thus, the dimensions of the metal plate are 10 dm and 8 dm.