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4 years ago

-18 − (-5) = SOLVE PLEASE

Mathematics

2 answers:

Alexus [3.1K]4 years ago

7 0

Answer:

-13

Brainliest would be appreciated

Mademuasel [1]4 years ago

6 0

Answer:

-13

Step-by-step explanation:

Subtracting a negative is like adding a positive. 18-5 is 13. The bigger number 18 was originally a negative thus our answer must be in negative form.

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The green county sale tax rate is 6.5%. What is the total cost of purchasing a pair of shoes for $35 and a shirt for $22

dezoksy [38]

$60.71! Add $35 and $22 together, which is $57. Multiply that by 6.5% (0.065), which produces 3.705, which rounds down to $3.71. Add $3.71 to $57, and voila!

6 0

3 years ago

What is the median of this set of data?<br>NA<br>66,51, 77, 68, 60, 75, 54, 80

vagabundo [1.1K]

The median is of this set of data is 67

8 0

3 years ago

Read 2 more answers

Please answer this correctly

Lubov Fominskaja [6]

Answer:

538

Step-by-step explanation:

l x w

7x39

12x20

5x5

538

5 0

3 years ago

4x-3y=12 and y=7x-4?

Natalka [10]

Are these simultaneous questions or like seperate ones?

Simultaneous:
4x -3(7x-4) = 12
4x - 21x + 12 = 12
-17x = 0
X = 0

Therefore y = -4

***
If it's a graph
x int: (3,0)
Y int: (0, -4)

Um idk if that's the answers you wanted but I hope it helped somehow??

5 0

3 years ago

A civil engineer is analyzing the compressive strength of concrete. Compressive strength is approximately normally distributed w

nignag [31]

Answer:

a) $3250-1.96\frac{31.623}{\sqrt{18}}=3232.108$

$3250+1.96\frac{31.623}{\sqrt{18}}=3267.892$

So on this case the 95% confidence interval would be given by (3232.108;3267.892)

b) For this case since the value of 3270 is higher than the upper limit for the confidence interval so we can conclude that the true mean is not higher than 3270 at 5% of signficance. We can reject the claim at the significance level of 5%.

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".

$\bar X= 3250$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma^2 =1000$ represent the sample standard variance

$s = \sqrt{1000}$ represent the sample deviation

n=12 represent the sample size

Part a

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 0.95 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: "=-NORM.INV(0.025,0,1)".And we see that $z_{\alpha/2}=1.96$

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

$3250-1.96\frac{31.623}{\sqrt{18}}=3232.108$

$3250+1.96\frac{31.623}{\sqrt{18}}=3267.892$

So on this case the 95% confidence interval would be given by (3232.108;3267.892)

Part b

For this case since the value of 3270 is higher than the upper limit for the confidence interval so we can conclude that the true mean is not higher than 3270 at 5% of signficance. We can reject the claim at the significance level of 5%.

8 0

3 years ago