Ellie is now 4 time as old as her son. In 5 years time she is going to be 3 times as old as her son. How old is eliies son now?

Is this a function or not a function? (Picture)

musickatia [10]

It is not a function

4 0

3 years ago

Two different types of polishing solutions are being evaluated for possible use in a tumble-polish operation for manufacturing i

Nina [5.8K]

Answer:

$z=\frac{0.843-0.653}{\sqrt{0.748(1-0.748)(\frac{1}{300}+\frac{1}{300})}}=5.358$

$p_v =2*P(Z>5.358) = 4.2x10^{-8}$

Comparing the p value with the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that we have singificantly differences between the two proportions.

Step-by-step explanation:

Data given and notation

$X_{1}=253$ represent the number with no defects in sample 1

$X_{2}=196$ represent the number with no defects in sample 1

$n_{1}=300$ sample 1

$n_{2}=300$ sample 2

$p_{1}=\frac{253}{300}=0.843$ represent the proportion of number with no defects in sample 1

$p_{2}=\frac{196}{300}=0.653$ represent the proportion of number with no defects in sample 2

z would represent the statistic (variable of interest)

$p_v$ represent the value for the test (variable of interest)

$\alpha=0.05$ significance level given

Concepts and formulas to use

We need to conduct a hypothesis in order to check if is there is a difference in the the two proportions, the system of hypothesis would be:

Null hypothesis: $p_{1} - p_2}=0$

Alternative hypothesis: $p_{1} - p_{2} \neq 0$

We need to apply a z test to compare proportions, and the statistic is given by:

$z=\frac{p_{1}-p_{2}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{1}}+\frac{1}{n_{2}})}}$ (1)

Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{253+196}{300+300}=0.748$

z-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

Calculate the statistic

Replacing in formula (1) the values obtained we got this:

$z=\frac{0.843-0.653}{\sqrt{0.748(1-0.748)(\frac{1}{300}+\frac{1}{300})}}=5.358$

Statistical decision

Since is a two sided test the p value would be:

$p_v =2*P(Z>5.358) = 4.2x10^{-8}$

Comparing the p value with the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that we have singificantly differences between the two proportions.

5 0

3 years ago

Please asap I need this for a test

ki77a [65]

Answer:

3

Step-by-step explanation:

(f O g) this basically means that the input x first goes trough the function g and then f. Like f(g(x)).

So when x went trough g, you got the output g(x) and then this went trough f and you got f(g(x)) = -8 = 'f(x)'.

With this in mind you can retrace your steps by first looking at what input can get -8 as an output, for f this is -4. this means g(x) = -4

Then you look at what input (this is the x you're looking for) gets you the ouput -4. Looking at the second image you'll picture see that it's the input 3.

4 0

2 years ago

Find the value of x. *<br> I think I’m a little off

DiKsa [7]

Answer:

x = 44

Step-by-step explanation:

3x - 5 is complementary to y° so their sum is 180°

The angle with measure 127° is also complementary with y°

127 + y = 180

y = 53°

53 + 3x - 5 = 180

3x + 48 = 180

3x = 132

x = 44

6 0

3 years ago

In 2015, I’m buffalo, New York, there were 8,625 arrest, 2,678 robberies, 865 assaults, and 20 murders. The population of Buffal

Nutka1998 [239]

865:2678 is the answer

8 0

3 years ago