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4 years ago

Emma is solving 16-8=4(+6) what should be her first step?

Mathematics

1 answer:

kicyunya [14]4 years ago

4 0

Answer:

Foil out the 4 to both the star and 6, giving you 16-8star = 4star + 24

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I need help for this question plz

ExtremeBDS [4]

Y=180-69=111
4x+7=y
4x+7=111
4x=111-7
4x=104
X=26

Answer: x=26, y=111

4 0

4 years ago

A random sample of 100 teletype operators indicates that their salaries fluctuate quite a bit. The sample Standard deviation of

ELEN [110]

Answer:

$\frac{(99)(10)^2}{123.225} \leq \sigma^2 \leq \frac{(99)(10)^2}{77.046}$

$80.341 \leq \sigma^2 \leq 128.495$

Now we just take square root on both sides of the interval and we got:

$8.963 \leq \sigma \leq 11.336$

Step-by-step explanation:

Data given and notation

s=10 represent the sample standard deviation

$\bar x$ represent the sample mean

n=100 the sample size

Confidence=90% or 0.90

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 mean or variance 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.

The Chi Square distribution is the distribution of the sum of squared standard normal deviates .

Calculating the confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

The next step would be calculate the critical values. First we need to calculate the degrees of freedom given by:

$df=n-1=100-1=99$

Since the Confidence is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical values.

The excel commands would be: "=CHISQ.INV(0.05,99)" "=CHISQ.INV(0.95,99)". so for this case the critical values are:

$\chi^2_{\alpha/2}=123.225$

$\chi^2_{1- \alpha/2}=77.046$

And replacing into the formula for the interval we got:

$\frac{(99)(10)^2}{123.225} \leq \sigma^2 \leq \frac{(99)(10)^2}{77.046}$

$80.341 \leq \sigma^2 \leq 128.495$

Now we just take square root on both sides of the interval and we got:

$8.963 \leq \sigma \leq 11.336$

5 0

3 years ago

Name the kind or kinds of symmetry the following figure has: A

denpristay [2]

It is a straight line of symmetry because if you have a paper A and you fold it, it will form a straight line, and that is also meaning a straight line of symmetry. If you fold it any other way, it will not be a line of symmetry.

Hope this helps you ;)

6 0

3 years ago

A tape manufacturer has created a new formula that is supposed to be more adhesive on all types of surfaces. Managers wish to co

taurus [48]

Answer:

This is an experiment with blocking ( B )

Step-by-step explanation:

The best way to describe this experiment is an experiment with blocking this is because the Type of surface where the tape is been tested can be considered a blocking variable while the weights can be considered as treatments

A blocking variable is a variable used in experiment which is not of primary interest to the experiment observer ( I.e. The tape is supposed to hold on all types of surfaces and not just on Aluminum and wood surface )

8 0

3 years ago

Write 2/3 with the denominator 12

Nataly_w [17]

Answer:

8/12

Step-by-step explanation:

First

12 divided by 3 = 4

Second

since 12/3=4 you multiply 3x4 to get 12 so what you do to the denominator you do to the numerator so 2x4=8

Last

so that would give you

2/3 = 8/12

5 0

3 years ago

Emma is solving 16-8*=4(*+6) what should be her first step?

Emma is solving 16-8=4(+6) what should be her first step?