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2 years ago

Find the solutions to x² = 20.

Mathematics

1 answer:

snow_tiger [21]2 years ago

7 0

Answer:

$x = \pm2 \sqrt 5$

Step-by-step explanation:

$~~~~~~x^2=20\\\\\implies x = \pm\sqrt{20}\\\\\implies x = \pm \sqrt{ 4 \times 5}\\\\\implies x = \pm2 \sqrt 5$

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Function or not?please heeeeeelp

Lynna [10]

Answer:

not a function

Step-by-step explanation:

the vertical line test. if you can put a vertical line on the graph that goes through two points on the parrabola it is not a function

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4 years ago

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Why is the median better to represent the data of a stem and leaf plot? I NEED THE ANSWER NOW PLSSSS

jeyben [28]

Answer:

The median value is better because it is not affected by the skewness of the data

Step-by-step explanation:

The median is better in representing the data of a stem and leaf plot because the median value is not affected so much by outliers and skewness of the data. for example: for a downward skewed stem and leaf plot the value of the median is greater than the mean value

Hence the median value is a better representation of the central tendency

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3 years ago

PLEASE HELP

jenyasd209 [6]

Answer:

Step-by-step explanation:

F(x) results in a parabola with vertex (0,0) wich mean there is only one x-int at that point. g(x) has been shifted the grapgh of f(x) to the right by to units and down by three unites. Now our vertex lies in the point (2,-3) and since the graph was move dow i=of the x-axis we now have two different x-intercepts.

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3 years ago

Fairfield Homes is developing two parcels near Pigeon Fork, Tennessee. In order to test different advertising approaches, it use

evablogger [386]

Answer:

(1) Null Hypothesis, $H_0$ : $\mu_1 = \mu_2$

Alternate Hypothesis, $H_1$ : $\mu_1\neq \mu_2$

(2) Test statistics = -1.48

(3) At the 0.05 significance level, Fair field conclude that the population means are same.

Step-by-step explanation:

Let $\mu_1$ = mean annual family income for 12 people making inquiries at the first development

$\mu_2$ = mean annual family income for 24 people making inquiries at the second development

$s_1$ = standard deviation of annual family income for 12 people making inquiries at the first development

$s_2$ = standard deviation of annual family income for 24 people making inquiries at the second development

$n_1$ = sample of people of first development i.e. 12

$n_2$ = sample of people of second development i.e. 24

(1) Null Hypothesis, $H_0$ : $\mu_1 = \mu_2$ {population means are same}

Alternate Hypothesis, $H_1$ : $\mu_1\neq \mu_2$ {population means are different}

<u>DECISION RULE ;</u>

If the test statistics is less than the critical value of t from table at 5% significance level, then we will accept null hypothesis, $H_0$ .
If the test statistics is more than the critical value of t from table at 5% significance level, then we will reject null hypothesis, $H_0$ .

(2) The test statistics is given by;

$\frac{(X_1bar -X_2bar) - (\mu_1-\mu_2)}{s_p\sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ ~ $t_n__1+n_2-2$

where, $X_1bar$ = Sample mean income of people at first development

= $153,000

$X_2bar$ = Sample mean income of people at second development = $171,000

$s_1$ = $42,000 and $s_2$ = $30,000

$s_p= \sqrt{\frac{(n_1-1)s_1^{2}+(n_2-1)s_2^{2} }{n_1+n_2-2}}$ = $\sqrt{\frac{(12-1)42000^{2}+(24-1)30000^{2} }{12+24-2}}$ = 34344.30

Test statistics = $\frac{(153000 -171000) - 0}{34344.30\sqrt{\frac{1}{12}+\frac{1}{24} } }$ ~ $t_3_4$

= -1.48

(3) At 5% level of significance, t table gives critical value of 2.032 at 34 degree of freedom.Since our test statistics is less than the critical value of t so considering our decision rule, we will accept null hypothesis.

And conclude that population means are same.

4 0

4 years ago

Please help im being timed <br><br> Inverse of f(x)=15x+4

rusak2 [61]

Answer:

$f^{-1}$ (x) =

Step-by-step explanation:

let y = f(x), then rearrange making x the subject

y = $\frac{1}{5}$ x + 4 ( subtract 4 from both sides )

y - 4 = $\frac{1}{5}$ x ( multiply both sides by 5 to clear the fraction )

5y - 20 = x

Change y back into terms of x with x = $f^{-1}$ (x) , then

$f^{-1}$ (x) = 5x - 20

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3 years ago