Using the graph as a reference, select all statements that are true about a normal distribution of data.

Q8 Q3.) Solve the system by the substitution method.

inn [45]

Recall that $(x+y)^2=x^2+2xy+y^2$ . So we can add twice the first equation to the second one to get

$x^2+y^2+2xy=10+2\cdot3\iff(x+y)^2=16\implies x+y=\pm4$

Since $xy=3$ , we have $y=\dfrac3x$ $(x\neq0)$ so

$x+y=x+\dfrac3x=\pm4\implies x^2\mp4x+3=0$

If $x+y=4$ , then

$x^2-4x+3=(x-3)(x-1)=0\implies x=3,x=1\implies y=1,y=3$

If $x+y=-4$ , then

$x^2+4x+3=(x+1)(x+3)=0\implies x=-1,x=-3\implies y=-3,y=-1$

So the solution set is

$(x,y)\in\{(-3,1),(1,3),(-1,-3),(-3,-1)\}$

3 0

3 years ago

In a study of red/green color blindness, 700 men and 2850 women are randomly selected and tested. Among the men, 66 have red/gre

olga55 [171]

Answer:

$z=\frac{0.0943-0.00281}{\sqrt{0.0208(1-0.0208)(\frac{1}{700}+\frac{1}{2850})}}=15.197$

$p_v =P(Z>15.197) \approx 0$

If we compare the p value and using any significance level for example $\alpha=0.05$ always $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say the the proportion of men with red/green color blindness.is significanlty higher than the proportion of women with red/green color blindness.

Step-by-step explanation:

Data given and notation

$X_{M}=66$ represent the number of men with red/green color blindness.

$X_{W}=8$ represent the number of women with red/green color blindness.

$n_{M}=700$ sample of male slected

$n_{W}=2850$ sample of female selected

$p_{M}=\frac{66}{700}=0.0943$ represent the proportion of male with red/green color blindness.

$p_{W}=\frac{8}{2850}=0.00281$ represent the proportion of female with red/green color blindness.

z would represent the statistic (variable of interest)

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

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the proportion of men with red/green color blindness. is higher than the proportionof women with red/green color blindness. , the system of hypothesis would be:

Null hypothesis: $p_{M} \leq p_{W}$

Alternative hypothesis: $p_{M} > p_{W}$

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

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

Where $\hat p=\frac{X_{M}+X_{W}}{n_{M}+n_{W}}=\frac{66+8}{700+2850}=0.0208$

Calculate the statistic

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

$z=\frac{0.0943-0.00281}{\sqrt{0.0208(1-0.0208)(\frac{1}{700}+\frac{1}{2850})}}=15.197$

Statistical decision

For this case we don't have a significance level provided $\alpha$ , but we can calculate the p value for this test.

Since is a one side test the p value would be:

$p_v =P(Z>15.197) \approx 0$

If we compare the p value and using any significance level for example $\alpha=0.05$ always $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say the the proportion of men with red/green color blindness.is significanlty higher than the proportion of women with red/green color blindness.

8 0

3 years ago

you sign up for a 13 weeks of swim lessons. There is 26$ sign up-fee. The cost is 325$.What is the cost per week

VLD [36.1K]

Your awnser is 325 per week

5 0

3 years ago

Read 2 more answers

April and Cody invest $5,000 each at their local bank. April invests at a 4% simple interest rate, and Cody invests at a 4% inte

maria [59]

Answer:

$24.32

Step-by-step explanation:

<u>The difference in balances is:</u>

5000*(1 + 0.04)^3 - 5000*(1 + 0.04*3) =
5624.32 - 5600 =
24.32

3 0

3 years ago

A help would be greatly appreciated!

dalvyx [7]

The tree was approximately 40.8ft tall.

You use the equation, a^2+b^2=c^2.
12^2 + 39^2 = x^2, add the results of 12^2 and 39^2 to make 1665 = x^2. You can take the positive root of both sides, 3√185, and it equals 40.80441152, which is rounded to 40.8.

7 0

4 years ago