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4 years ago

FREE POINTS JUST ANSWER

Mathematics

2 answers:

Archy [21]4 years ago

7 0

7 x 3 +3 is one
REST IN THE COMMENTS!

marshall27 [118]4 years ago

3 0

You have to do 7x3=21-3=18+7=24 I hope this helps

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PLS HELP ASAP ILL GIVE BRAINLKEST THANKS

Arisa [49]

Answer:

(4,4)

Step-by-step explanation:

hope this help

4 0

3 years ago

Read 2 more answers

A magazine conducts an annual survey in which readers rate their favorite cruise ship. All ships are rated on a 100-point scale,

Lyrx [107]

Answer:

a) The point of estimate for $\mu_1 -\mu_2$ is just given by:

$\bar X_1 -\bar X_2 =85.82-81.90=3.92$

b) $SE=\sqrt{(\frac{4.55^2}{35}+\frac{3.97^2}{44})}=0.975$

And the Margin of error is given by:

$Me= z_{\alpha/2} * SE=1.96*0.975=1.910$

c) The 95% confidence interval would be given by $2.009 \leq \mu_1 -\mu_2 \leq 5.83$ .

Step-by-step explanation:

Notation and previous concepts

$n_1 =35$ represent the sample of ships that carry fewer than 500 passengers

$n_2 =44$ represent the sample of ships that carry 500 or more passengers

$\bar x_1 =85.82$ represent the mean sample of of ships that carry fewer than 500 passengers

$\bar x_2 =81.90$ represent the mean sample of of ships that carry 500 or more passengers

$\sigma_1 =4.55$ represent the population deviation of ships that carry fewer than 500 passengers

$\sigma_2 =3.97$ represent the sample deviation of ships that carry 500 or more passengers

$\alpha=0.05$ represent the significance level

Confidence =95% or 0.95

The confidence interval for the difference of means is given by the following formula:

$(\bar X_1 -\bar X_2) \pm z_{\alpha/2}\sqrt{(\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2})}$ (1)

Part a

The point of estimate for $\mu_1 -\mu_2$ is just given by:

$\bar X_1 -\bar X_2 =85.82-81.90=3.92$

Part b: At 95% confidence, what is the margin of error?

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 $z_{\alpha/2}=1.96$

The standard error is given by the following formula:

$SE=\sqrt{(\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2})}$

And replacing we have:

$SE=\sqrt{(\frac{4.55^2}{35}+\frac{3.97^2}{44})}=0.975$

And the Margin of error is given by:

$Me= z_{\alpha/2} * SE=1.96*0.975=1.910$

Part c: What is a 95% confidence interval estimate of the difference between the population mean ratings for the two sizes of ships?

Confidence interval

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

$3.92-1.96\sqrt{(\frac{4.55^2}{35}+\frac{3.97^2}{44})}=2.009$

$3.92+1.96\sqrt{(\frac{4.55^2}{35}+\frac{3.97^2}{44})}=5.830$

So on this case the 95% confidence interval would be given by $2.009 \leq \mu_1 -\mu_2 \leq 5.83$ .

7 0

3 years ago

An astronaut who weighs 126 pounds on Earth weighs only 21 pounds on

3241004551 [841]

Answer:

186 pounds

Step-by-step explanation:

let x = pounds on Earth

set up a proportion: $\frac{126}{21}$ = $\frac{x}{31}$

cross-multiply: 21x = 3906

divide by 21: x = 186

3 0

3 years ago

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jonah earned $5 more than half of karen’s salary, k. which of the following expressions represents jonahs earnings

MrMuchimi

Answer: one half(k + 5)

one halfk + 5

one half + k + 5

one halfk > 5

Step-by-step explanation:

6 0

4 years ago

Read 2 more answers

Giselle works as a carpenter and as a blacksmith.

Strike441 [17]

She worked for 12 hours as a carpenter and 18 hours as a black smith

7 0

3 years ago