Suppose Alex has 3x stamps, Freddy has 5x stamps. After Freddy gives Alex 10 stamps, Alex has 3x+10 while Freddy has 5x-10
the new ratio is 7 to 9, so we have the equation: (3x+10)/(5x-10)=7/9
9(3x+10)=7(5x-10)
27x+90=35x-70
160=8x
x=20
So Alex has 3*20=60 stamps while Freddy has 5*20=100. Together they have 160

4 0

2 years ago

Can someone please explain y=mx+b

lana [24]

$y=mx+b$ is slope-intercept form, which is a way of writing an equation for a line.

In this equation, $m$ represents the slope and $b$ represents the y-intercept.

$x$ and $y$ are the coordinates of a point on the resulting line.

Here are some examples:

$y=3x+2$

$y=-2x-4$

$y=8x-1$

$y=-7x+5$

7 0

3 years ago

To obtain information on the corrosion-resistance properties of a certain type of steel conduit, 45 specimens are buried in soil

Fiesta28 [93]

Answer:

The sample has not met the required specification.

Step-by-step explanation:

As the average of the sample suggests that the true average penetration of the sample could be greater than the 50 mils established, we formulate our hypothesis as follow

$H_0$ : The true average penetration is 50 mils

$H_a$ : The true average penetration is > 50 mils

Since we are trying to see if the true average is greater than 50, this is a right-tailed test.

If the level of confidence is α = 0.05 then the $z_\alpha$ score against we are comparing with, is 1.64 (this is because the area under the normal curve N(0;1) to the right of 1.64 is 0.05)