Hey there!
Let's set up an algebraic equation to represent this problem:

In order to get rid of the squared, we need to take the square root of both sides, therefore, our answer is:

Your answer is the square root of 20.
Hope this helps!
Step-by-step explanation:
3/8 = 0.375
5/8 = 0.625
4.375 - 1.625
= 2.75
B- use Desmos it helps a lot!
Answer:
multiply the left side of the constant vector by the inverse matrix
Step-by-step explanation:
The matrix equation ...
AX = B
is solved by left-multiplying by the inverse of A:
A⁻¹AX = A⁻¹B
IX = A⁻¹B . . . . . the result of multiplying A⁻¹A is the identity matrix
X = A⁻¹B . . . . . B needs to be multiplied by the inverse matrix
![\left[\begin{array}{c}x&y\end{array}\right] = \left[\begin{array}{cc}-4&1\\3&2\end{array}\right]^{-1}\left[\begin{array}{c}9&7\end{array}\right]=\dfrac{1}{11}\left[\begin{array}{cc}-2&1\\3&4\end{array}\right]\left[\begin{array}{c}9&7\end{array}\right]=\left[\begin{array}{c}-1&5\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%26y%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-4%261%5C%5C3%262%5Cend%7Barray%7D%5Cright%5D%5E%7B-1%7D%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D9%267%5Cend%7Barray%7D%5Cright%5D%3D%5Cdfrac%7B1%7D%7B11%7D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-2%261%5C%5C3%264%5Cend%7Barray%7D%5Cright%5D%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D9%267%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D-1%265%5Cend%7Barray%7D%5Cright%5D)
Answer:
81 samples
Step-by-step explanation:
According to the empirical rule :
Possible values of the sample mean is within 3 standard deviations of the population mean :
μ ± 3 sd(x) ; sd(x) = standard deviation of sampling distribution.
3 * sd(x) = 1
sd(x) = 1/3
Recall:
Standard deviation of sampling distribution, sd(x)
sd(x) = σ / sqrt(n)
1/3 = 3 / sqrt(n)
Square both sides
1/9 = 9/n
Cross multiply :
n * 1 = 9 * 9
n = 81