Ray made an error while solving the following equation. In which step did ray make an error?

Mathematics

2 answers:

raketka [301]2 years ago

7 0

He made an error is step 2

3x + 18 = 2x +8

subtract 2x from each side

x + 18 = 8

Anna35 [415]2 years ago

5 0

Answer:

Step-by-step explanation:

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If only two points are needed to determine a line, why are three ordered pair solutions or points found for a linear equation?

Alina [70]

To draw the graph of a linear equation , two points are more than enough to draw a line.

But sometimes we may commit a mistake and then if we draw the line, everything appears good. As two points shall always define a line irrespective of the points are correct or not.

So in order to make sure that the points we obtained are correct , we take a third point to ensure that the two points calculated earlier are correct and all points lie on the same line. If they don't we have committed some mistake.

Option A) is the right answer

7 0

2 years ago

Seams Personal advertises on its website that 95% of customer orders are received within four working days. They performed an au

Bezzdna [24]

Answer:

a. Yes(n=500>=5, n(1-p)=25>=5)

b. 0.15241

Step-by-step explanation:

a. A normal approximation to the binomial can be used $n\geq$ 5 and n(1-p)>=5:

#We calculate our p as follows:

$\hat p$ =x/n=470/500=0.94

n=500

n(1-p)=500(1-0.95)=25

Hence, we can use the normal approximation.

b. This is a normal approximation.

-Given that p=0.95(95%)

-We verify if our distribution can be approximated to a normal:

$np=0.95\times 500=475\\n(1-p)=500(1-0.95)=25\\\\np\geq 5,\ n(1-p)\geq 5$

Hence, we can use the normal approximation of the form:

$P_{bin}(k,n,p)->N(\mu,\sigma^2)\left \{ {{\mu=np=475} \atop {\sigma=\sqrt{np(1-p)}=4.8734}} \right. \\\\\\P_{bin}(k\leq 470)\approx P_{norm}(x\leq 470.5)=P_{norm}(z\leq \frac{470-475}{4.8734})\\\\P_{norm}(z\leq -1.0260)=0.15241$