Simplify the expression. -(6)-1 A: -1/6 B: 1/6 C: 6 D: -1

Can someoneeee helpppp

Kazeer [188]

Answer:

2

Step-by-step explanation:

Because when solving the inequality you end up with 2 $\geq$ x

4 0

3 years ago

A guitar had been marked down by 34% and sold for $825.

qaws [65]

Answer:

$1105.5

Step-by-step explanation:

825 X 0.34 =280.5

The 0.34 is the 34%

280.5 is what was discounted.

Then add 280.5 to 825 and that adds up to 1105.5

8 0

4 years ago

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard devia

Arturiano [62]

Answer:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (3)

$n=(\frac{2.58(54.5)}{5})^2 =790.846 \approx 791$

So the answer for this case would be n=791 rounded up to the nearest integer

Step-by-step explanation:

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

Solution to the problem

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

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

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (2)

And on this case we have that ME =+5 and we are interested in order to find the value of n, if we solve n from equation (2) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (3)

$n=(\frac{2.58(54.5)}{5})^2 =790.846 \approx 791$

So the answer for this case would be n=791 rounded up to the nearest integer

4 0

3 years ago

-14x + 15y = 15 -21x - 20y = -10 Use substitution to find the x and y coordinates.

denis-greek [22]

          -14x + 15y = 15
      -14x + 14x + 15y = 14x + 15
         15y = 14x + 15
          15    15
         y = ¹⁴/₁₅x + 1
   -21x - 20y = -10
   -21x - 20(¹⁴/₁₅x + 1) = -10
-21x - 20(¹⁴/₁₅x) - 20(1) = -10
       -21x - 18²/₃x - 20 = -10
      -39²/₃x - 20 = -10
      + 20 + 20
      -39²/₃x = 10
       -39²/₃   -39²/₃
   x = ⁻³⁰/₁₁₉
         y = ¹⁴/₁₅x + 1
   y = ¹⁴/₁₅(⁻³⁰/₁₁₉) + 1
   y = ⁻²⁸/₁₁₉ + 1
   y = ⁹¹/₁₁₉
      (x, y) = (⁻³⁰/₁₁₉, ⁹¹/₁₁₉)

8 0

3 years ago

Find X. please i need help with this

-BARSIC- [3]

Answer:

Step-by-step explanation:

X + X + 96 = 180 {SUM OF ANGLES OF TRIANGLE}

2X + 96 = 180

2X = 180 -96

2X =84

X = 84/2

X = 42

4 0

3 years ago

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