. Suppose that the average score in a statistics test is 84 with a standard deviation

Mathematics

1 answer:

julia-pushkina [17]3 years ago

4 0

Answer:

Step-by-step explanation:

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Someone pls help asap this is due tmrw !!<br><br> x - 3y = -12<br> 2x + 3y = 3

hram777 [196]

Answer:

Step-by-step explanation:

to solve this system of equations we will add them

x-3y=-12

2x+3y=3 now +3y-3y=0

3x=-12+3

3x=-9

x=-3

plug in the first equation

-3-3y=-12

-3y=-12+3

-3y=-9

y=3

4 0

3 years ago

A coach purchases 47 hats for his players and their families at a total cost of $302. The cost of a small hat is $5.50. A medium

frosja888 [35]

Answer:

The answer is below

Step-by-step explanation:

Let x represent the number of small hat purchased, y represent the number of medium hat purchased and z represent the number of large hat purchased.

Since a total of 47 hats where purchased, hence:

x + y + z = 47 (1)

Also, he spent a total of $302, hence:

5.5x + 6y + 7z = 302 (2)

He purchases three times as many medium hats as small hats, hence:

y = 3x

-x + 3y = 0 (3)

Represent equations 1, 2 and 3 in matrix form gives:

$\left[\begin{array}{ccc}1&1&1\\5.5&6&7\\-3&1&0\end{array}\right] \left[\begin{array}{c}x\\y\\z\end{array}\right] = \left[\begin{array}{c}47\\302\\0\end{array}\right] \\\\\\\\ \left[\begin{array}{c}x\\y\\z\end{array}\right] =\left[\begin{array}{ccc}1&1&1\\5.5&6&7\\-3&1&0\end{array}\right] ^{-1} \left[\begin{array}{c}47\\302\\0\end{array}\right] \\\\\\ \left[\begin{array}{c}x\\y\\z\end{array}\right] = \left[\begin{array}{c}6\\18\\23\end{array}\right]$