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4 years ago

Solve:

1 answer:

s2008m [1.1K]4 years ago

8 0

I hope this helps you

y+z=4-x

5x+4-x=16

4x=12

x=3

x+y+z+x-y+4z=4+27

2x+5z=31

2.3+5z=31

5z=25

z=5

x+y+z=4

3+y+5=4

y=-4

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$200 in the bank account if she writes 6 checks for exactly $19.98 what expression describes the change in her bank account

Ad libitum [116K]

Step-by-step explanation:

$200 - 6 \times 19.98$

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3 years ago

Read 2 more answers

Simplify. 2 x (3-1) + 3

Natali [406]

Steps to solve:

2 * (3 - 1) + 3

~Simplify

2 * (2) + 3

~Multiply

4 + 3

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Best of Luck!

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3 years ago

Starting with the graph of f(x) = 5^{x}, write the equation of the graph that results from (a) shifting f(x) 1 units downward. y

aev [14]

1 down, means minus 1 from whole equation
moving 1 to left means add 1 to every x
reflecting across x axis means multiply every x by -1

a. $y=5^x+1$
b. $y=5^{x+1}$
c. $y=5^{-x}$

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3 years ago

Suppose the method of tree ring dating gave the following dates A.D. for an archaeological excavation site. Please show your wor

natita [175]

Answer:

a) $\bar X=\frac{1245+1245+1321+1191+1295+1330+1239+1250+1228}{9}= 1260.444$

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

And if we replace we got:

$s = 45.580$

c) For this case since the sampel size is n=9 <30 we can use the t distribution in order to find the confidence interval.

d) $1260.444-2.306 \frac{45.580}{\sqrt{9}}= 1225.408$

$1260.444+2.306 \frac{45.580}{\sqrt{9}}= 1295.480$

Step-by-step explanation:

For this case we ave the following data:

1245 1245 1321 1191 1295 1330 1239 1250 1228

Part a

We can calculate the sample mean with the following formula:

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

And if we replace we got:

$\bar X= \frac{1245+1245+1321+1191+1295+1330+1239+1250+1228}{9}= 1260.444$

Part b

For this case we can use the following formula in order to find the sample standard deviation:

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

And if we replace we got:

$s = 45.580$

Part c

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".

For this case since the sampel size is n=9 <30 we can use the t distribution in order to find the confidence interval.

Part d

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

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

We need to find the degrees of freedom given by:

$df = n-1 = 9-1=8$

Since the Confidence is 0.95 or 95%, the value of $\alpha=1-0.95=0.05$ 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(0.025,8)".And we see that $t_{\alpha/2}=2.306$

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

$1260.444-2.306 \frac{45.580}{\sqrt{9}}= 1225.408$

$1260.444+2.306 \frac{45.580}{\sqrt{9}}= 1295.480$

8 0

4 years ago

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MArishka [77]

Add the table please for assistance in this problem

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4 years ago