Y is 5 less than the product of 4 and x

denis23 [38]

Answer:

The answer is (x,y)=(-3,-2)

Step-by-step explanation:

I used the comparison method because I dont know what type of method you needed, sorry. The methods I know would be: the Comparison Method (what I used), the Substitution Method, Elimination Method,Inverse Matrix Method, Cramer's Rule, and the Gauss-Jordan Method.

You can also rewrite this equation to 3x-y=-7 and x-y=-1.

I'm sorry, I dont know what kind of answer you're looking for. I really hope this helps.

7 0

3 years ago

A standard weight known to weigh 10 grams. Some suspect bias in weights due to manufacturing process. To assess the accuracy of

notsponge [240]

Answer:

a) The 98% confidence interval for the mean weight is between 10.00409 grams and 10.00471 grams

b) 49 measurements are needed.

Step-by-step explanation:

Question a:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.98}{2} = 0.01$

Now, we have to find z in the Ztable as such z has a pvalue of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.01 = 0.99$ , so Z = 2.327.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 2.327\frac{0.0003}{\sqrt{5}} = 0.00031$

The lower end of the interval is the sample mean subtracted by M. So it is 10.0044 - 0.00031 = 10.00409 grams

The upper end of the interval is the sample mean added to M. So it is 10 + 0.00031 = 10.00471 grams

The 98% confidence interval for the mean weight is between 10.00409 grams and 10.00471 grams.

(b) How many measurements must be averaged to get a margin of error of +/- 0.0001 with 98% confidence?

We have to find n for which M = 0.0001. So

$M = z\frac{\sigma}{\sqrt{n}}$

$0.0001 = 2.327\frac{0.0003}{\sqrt{n}}$

$0.0001\sqrt{n} = 2.327*0.0003$

$\sqrt{n} = \frac{2.327*0.0003}{0.0001}$

$(\sqrt{n})^2 = (\frac{2.327*0.0003}{0.0001})^2$

$n = 48.73$

Rounding up

49 measurements are needed.

7 0

3 years ago

The probability of rain =0.2, sun=0.3,cloud=0.5. What is the probability of rain and sun over a two day period?

svp [43]

Answer:

0.2752512

Step-by-step explanation:

The formula you are looking for is the binomial probability:

n!

P (X) = ------------ * (P)^X * (q)^n - X

(n- X)! X!

For your particular problem:

n=7

X=2

q = 1-p = .8

7!/(5!*2!)*(.2)^2*(.8)^5 = 0.2752512

Hope this helps, have a nice day/night! :D

6 0

2 years ago

A point in rectangular coordinates is given. Convert the point to polar coordinates. Round your answers to two decimal places.

postnew [5]

Answer:

(√74, 54.46°)

Step-by-step explanation:

The rectangular coordinate point is given as; (5, 7)

Now, converting rectangular coordinates to polar coordinates is done by;

(r, θ)

Where, r is the magnitude while θ is the angle

r = √(5² + 7²)

r = √74

tan θ = (7/5)

θ = tan^(-1) 1.4

θ = 54.46°

Thus,polar coordinate is; (√74, 54.46°)

3 0

2 years ago

Ricky had 21 video games. He traded in 16 games for store credit. How many video games does Ricky have left?

Margaret [11]

21-16= 5
21 minus 16 equals 5

8 0

3 years ago

Read 2 more answers