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4 years ago

Please help!

Mathematics

1 answer:

Kay [80]4 years ago

6 0

Answer:

Step-by-step explanation:

$\big7^{14}\div\big7^2=\big7^{14-2}=\big7^{12}$

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Is 600 km greater equal or less than 5 m

Elodia [21]

Answer:

It is greater

Step-by-step explanation:

600 km = 600,000 m

4 0

4 years ago

Rhett made a simple drawing of his house. it is a three dimensional figure with four faces that are rectangular and two that are

Xelga [282]

Answer: Rectangular prism

Step-by-step explanation:

Details culled from the information supplied :

1.) A 3 - dimensional figure

2.) Four rectangular faces

3.) Two square faces

Using the above information to form the basis of our inference, It could be inferred that the figure of Rhett's house is a rectangular prism.

Three dimensions: length, width, and height

Six faces in total; four of which are rectangular and 2 squared faces.

6 0

4 years ago

Hey will give brainliest

NeTakaya

Answer:

Step-by-step explanation:

i just had this problem

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4 years ago

A random sample of n measurements was selected from a population with unknown mean mu and standard deviation sigmaequals50 for e

Andre45 [30]

Answer:

a) (26.50;57.50)

b) (117.34;128.66)

c) (12.13;27.87)

d) (-4.73;11.01)

e) No. Since the sample sizes are large (n ≥ 30), the central limit theorem guarantees that $\bar x$ is approximately normal, so the confidence intervals are valid

Step-by-step explanation:

The central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".

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".

The confidence interval is given by this formula:

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

And for a 95% of confidence the significance is given by $\alpha=1-0.95=0.05$ , and $\frac{\alpha}{2}=0.025$ . Since we know the population standard deviation we can calculate the critical value $z_{0.025}= \pm 1.96$

Part a

$n=40,\bar X=42,\sigma=50$

If we use the formula (1) and we replace the values we got:

$42 - 1.96 \frac{50}{\sqrt{40}}=26.50$

$42 + 1.96 \frac{50}{\sqrt{40}}=57.50$

The 95% confidence interval is given by (26.50;57.50)

Part b

$n=300,\bar X=123,\sigma=50$

If we use the formula (1) and we replace the values we got:

$123 - 1.96 \frac{50}{\sqrt{300}}=117.34$

$123 + 1.96 \frac{50}{\sqrt{300}}=128.66$

The 95% confidence interval is given by (117.34;128.66)

Part c

$n=155,\bar X=20,\sigma=50$

If we use the formula (1) and we replace the values we got:

$20 - 1.96 \frac{50}{\sqrt{155}}=12.13$

$20 + 1.96 \frac{50}{\sqrt{155}}=27.87$

The 95% confidence interval is given by (12.13;27.87)

Part d

$n=155,\bar X=3.14,\sigma=50$

If we use the formula (1) and we replace the values we got:

$3.14 - 1.96 \frac{50}{\sqrt{155}}=-4.73$

$3.14 + 1.96 \frac{50}{\sqrt{155}}=11.01$

The 95% confidence interval is given by (-4.73;11.01)

Part e

No. Since the sample sizes are large (n ≥ 30), the central limit theorem guarantees that $\bar x$ is approximately normal, so the confidence intervals are valid

8 0

3 years ago

How does the test variable of an object affect the amount of mechanical energy it contains?

stiv31 [10]

Answer:

rg53º

Step-by-step explanation:

grnrgnrn

4 0

3 years ago