Can someone help me and show how to do it

Which equation represents a line that is parallel to the line y = - 4x +5?

Vikentia [17]

Y= -4x+3

slope is still the same so it would be parallel to that line. Only the y-intercept is different so it would just pass through a different point

6 0

3 years ago

Read 2 more answers

The table shows the travelling time to work of 50 people.

Crank

Answer:

24.8 mins

Step-by-step explanation:

Time > timemark > frequency

0 – 10 > 10/2 = 5 > 5

10 – 20 > (10+20)/2 = 15 > 15

20 – 30 > (20+30)/2 = 25 > 13

30 – 40 > (30+40)/2 = 35 > 10

40 – 50 > (40+50)/2 = 45 > 7

The mean time for the 50 people is given by:

Mean = summation (mid time x frequency) / total frequency

Mean = [5x5 + 15x15 + 25x13 + 35x10 + 45x7] / 50

Mean = [25 + 225 + 325 + 350 + 315] / 50

Mean = 1240 / 50

Mean = 24.8 mins

8 0

3 years ago

Read 2 more answers

What is the axis of symmetry for the graph of y – 4x = 7 – x2

eimsori [14]

we know that

The equation in vertex form of a vertical parabola is equal to

$y=a(x-h)^{2}+k$

where

(h,k) is the vertex of the parabola

and the axis of symmetry is equal to the x-coordinate of the vertex

so

$x=h$ -----> equation of the axis of symmetry

In this problem we have

$y-4x=7-x^{2}$

Convert to vertex form

Group terms that contain the same variable, and move the constant to the opposite side of the equation

$y-7=-x^{2}+4x$

$y-7=-(x^{2}-4x)$

Complete the square. Remember to balance the equation by adding the same constants to each side

$y-7-4=-(x^{2}-4x+4)$

$y-11=-(x^{2}-4x+4)$

Rewrite as perfect squares

$y-11=-(x-2)^{2}$

$y=-(x-2)^{2}+11$

the vertex is the point $(2,11)$

therefore

<u>the answer is</u>

The axis of symmetry is

$x=2$

see the attached figure to better understand the problem

5 0

4 years ago

Read 2 more answers

The health of the bear population in a park is monitored by periodic measurements taken from anesthetized bears. A sample of the

Vikki [24]

Answer:

$182.167-2.03\frac{114.05}{\sqrt{36}}=143.580$

$182.167+2.03\frac{114.05}{\sqrt{36}}=220.754$

So on this case the 95% confidence interval would be given by (143.580;220.754)

Step-by-step explanation:

Assuming the following dataset:

77, 349,417,349, 167 , 225, 265, 360,205

145,335,40,139, 177,108, 163, 202, 22

123,439, 125,135, 86,43, 217,49, 156

119,178, 151, 61, 350, 312, 91, 89,89

We can calculate the sample mean with the followinf formula:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}= 182.167$

And the sample deviation with:

$s = \sqrt{\frac{\sum_{i=1}^n (X_i-\bar X)^2}{n-1}}=114.05$

The sample size on this case is n =36.

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X=182.167$ represent the sample mean

$\mu$ population mean (variable of interest)

s=114.05 represent the sample standard deviation

n=36 represent the sample size

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

The point estimate of the population mean is $\hat \mu = \bar X =182.167$

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=36-1=35$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,35)".And we see that $t_{\alpha/2}=2.03$