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3 years ago

Please help :)

Mathematics

2 answers:

saveliy_v [14]3 years ago

8 0

Answer:

Step-by-step explanation:

For supplementary angle the sum is 180°

5x + 20 + 50 = 180

5x + 70 = 180

5x = 180 - 70

5x = 110

x = 110/5

x = 22°

bogdanovich [222]3 years ago

7 0

Step-by-step explanation:

B is the answer because

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Please answer the question in the picture!

Rama09 [41]

The correct answer is the second one, I already answered it.

8 0

3 years ago

It takes 1 gallon of gas to drive 25 miles. which measure of efficiency is this an example of

Brilliant_brown [7]

Are these the choices? <span>Cost, Time, Pace, Materials?

I think the answer would be - it is a measure of the efficiency of the materials used in the car. Since this talks about how many gallons of gas a drive of 25 miles would consume. </span>

8 0

3 years ago

23 degrees 20’48 is the same as _degrees.

allochka39001 [22]

Answer:

$\large\boxed{23^o20'48''=\left(23\dfrac{26}{75}\right)^o}$

Step-by-step explanation:

$\text{We know:}\\\\1^o=60'\to1'=\left(\dfrac{1}{60}\right)^o\\\\1'=60''\to1^o=(60)(60'')=3600''\to1''=\left(\dfrac{1}{3600}\right)^o\\\\23^o20'48''\\\\20'=\left(\dfrac{20}{60}\right)^o=\left(\dfrac{1}{3}\right)^o\\\\48''=\left(\dfrac{48}{3600}\right)^o=\left(\dfrac{1}{75}\right)^o\\\\\text{Therefore}\\\\23^o20'48''=23^o+20'+48''=23^o+\left(\dfrac{1}{3}\right)^o+\left(\dfrac{1}{75}\right)^o\\\\=\left(23+\dfrac{1\cdot25}{3\cdot75}+\dfrac{1}{75}\right)^o=\left(23+\dfrac{25}{75}+\dfrac{1}{75}\right)^o=\left(23\dfrac{26}{75}\right)^o$

4 0

3 years ago

1. Use the Law of Levers to solve the problem, x1y1=x2y2.

Mademuasel [1]

1) Never heard of someone referring to the Law of Levers before, must be showing my age. A system as you describe is at equilibrium when the net torque is equal to zero. Since torque is Fr=mgr so for this system we have a sum of:

27g*10+30g*x=0 The sum must be zero to be at equilibrium, dividing both sides by g you have:

270+30x=0

270=-30x

x=-9

The negative just indicates that the magnitude of 9 is on the opposite side of the fulcrum, so x=9ft in magnitude.

2) Inverse variation is of the form y=k/x, in this case we are given a point so we can solve for the constant, k, of variation...

y=k/x, and we are given y=-12 when x=5 so

-12=k/5

k=-60 so the equation is:

y=-60/x which can be expressed as

xy=-60

5 0

3 years ago

A sample of eight workers in a clothing manufacturing company gave the following figures for the amount of time(in minutes) need

lilavasa [31]

Answer:

$10.108 < \mu < 13.892$

Step-by-step explanation:

1) 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".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

We have the following distribution for the random variable:

$X \sim N(\mu , \sigma=0.45)$

And by the central theorem we know that the distribution for the sample mean is given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

2) Confidence interval

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

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

In order to calculate the mean and the sample deviation we can use the following formulas:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

The mean calculated for this case is $\bar X=12$

The sample deviation calculated $s=2.268$

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

$df=n-1=8-1=7$

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 tabel to find the critical value. The excel command would be: "=-T.INV(0.025,7)".And we see that $t_{\alpha/2}=2.36$

Now we have everything in order to replace into formula (1):

$12-2.36\frac{2.268}{\sqrt{8}}=10.108$

$12+2.36\frac{2.268}{\sqrt{8}}=13.892$

So on this case the 95% confidence interval would be given by (10.108;13.892)

$10.108 < \mu < 13.892$

7 0

3 years ago