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3 years ago

A train travels 75 miles in 55 minutes what is the average speed in miles per minute

Mathematics

1 answer:

nekit [7.7K]3 years ago

5 0

Answer:

1.36 miles per min

Step-by-step explanation:

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Help please!!!<br> (please show work)

Aleksandr [31]

78=.26x

divide both side by .26

and it will equal 300

when you calculate it it will be 3 but put 300

8 0

3 years ago

Read 2 more answers

10.

Kay [80]

Answer:

$\frac{(82)(2.4)^2}{104.139} \leq \sigma^2 \leq \frac{(82)(2.4)^2}{62.132}$

$4.535 \leq \sigma^2 \leq 7.602$

Now we just take square root on both sides of the interval and we got:

$2.2 \leq \sigma \leq 2.8$

And the best option would be:

A. 2.2 < σ < 2.8

Step-by-step explanation:

Information provided

$\bar X=32.1$ represent the sample mean

$\mu$ population mean

s=2.4 represent the sample standard deviation

n=83 represent the sample size

Confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

The degrees of freedom are given by:

$df=n-1=83-1=82$

The Confidence is given by 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , the critical values for this case are:

$\chi^2_{\alpha/2}=62.132$

$\chi^2_{1- \alpha/2}=104.139$

And replacing into the formula for the interval we got:

$\frac{(82)(2.4)^2}{104.139} \leq \sigma^2 \leq \frac{(82)(2.4)^2}{62.132}$

$4.535 \leq \sigma^2 \leq 7.602$

Now we just take square root on both sides of the interval and we got:

$2.2 \leq \sigma \leq 2.8$

And the best option would be:

A. 2.2 < σ < 2.8

3 0

3 years ago

4. Nine fruit juice bottles contain 4 1/2 litres of fruit juice between them.

brilliants [131]

Answer:

2 $\frac{1}{2}$ litres or 2.5 litres

Step-by-step explanation:

From the question, 9 fruit juice bottles contain 4 $\frac{1}{2}$ litres of fruit juice. Therefore, to find how many litres of fruit juice would be contained in 5 fruit juice bottles, you multiply 5 by 4 $\frac{1}{2}$ litres and you divide the product by 9.

i.e. Let the quantity of the fruit juice for 5 bottles be x.

9 juice bottles ===> 4 $\frac{1}{2}$ litres

5 juice bottles ===> x

∴x = $\frac{5 * 4\frac{1}{2} }{9} litres$