Which is bigger millimeters or centimeters?

Flow meters are installed in urban sewer systems to measure the flows through the pipes. In dry weatherconditions (no rain) the

ziro4ka [17]

Answer:

a) $\frac{(8)(30.23)^2}{20.09} \leq \sigma^2 \leq \frac{(8)(30.23)^2}{1.65}$

$363.90 \leq \sigma^2 \leq 4430.80$

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

$19.08 \leq \sigma \leq 66.56$

b) For this case we are 98% confidence that the true deviation for the population of interest is between 19.08 and 66.56

Step-by-step explanation:

423.6, 487.3, 453.2, 402.9, 483.0, 477.7, 442.3, 418.4, 459.0

Part a

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

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

On this case we need to find the sample standard deviation with the following formula:

$s=sqrt{\frac{\sum_{i=1}^8 (x_i -\bar x)^2}{n-1}}
And in order to find the sample mean we just need to use this formula:
[tex]\bar x =\frac{\sum_{i=1}^n x_i}{n}$

The sample deviation for this case is s=30.23

The next step would be calculate the critical values. First we need to calculate the degrees of freedom given by:

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

The Confidence interval is 0.98 or 98%, the value of $\alpha=0.02$ and $\alpha/2 =0.01$ , and the critical values are:

$\chi^2_{\alpha/2}=20.09$

$\chi^2_{1- \alpha/2}=1.65$

And replacing into the formula for the interval we got:

$\frac{(8)(30.23)^2}{20.09} \leq \sigma^2 \leq \frac{(8)(30.23)^2}{1.65}$

$363.90 \leq \sigma^2 \leq 4430.80$

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

$19.08 \leq \sigma \leq 66.56$

Part b

For this case we are 98% confidence that the true deviation for the population of interest is between 19.08 and 66.56

4 0

4 years ago

3

Anastaziya [24]

Answer:

2329 are girls out of 37 boys in school in 2366 total

8 0

4 years ago

Sohan can do a piece of work in 10 days. He worked at it

Inessa05 [86]

Answer:

5 days

Step-by-step explanation:

Sohan can do the whole thing in 10 days

he worked 5 days so he did half

and Mohan did the other half in 5 days

so their speeds are same

so if they worked together they'd do it in half the time

i.e 5 days

6 0

3 years ago

A ball is thrown upward from the top of a building. The function below shows the height of the ball in relation to sea level, f(

Marina86 [1]

$f(t) = -16t^{2} +48t + 100$
Average rate of change from t = 3 seconds to t = 5 seconds = $\frac{f(5)-f(3)}{5-3} = \frac{(-16( 5^{2})+48(5)+100)-(-16( 3^{2})+48(3)+100 }{2}=$ $\frac{(-16(25)+240+100)-(-16(9)+144+100)}{2} = \frac{(-400+240+100)-(-144+144+100)}{2}=$ $\frac{-60-100}{2} = \frac{-160}{2} = -80$

5 0

3 years ago

Please help me answer number 5

malfutka [58]

Step-by-step explanation:

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6 0

3 years ago