A cone has a height of 20 centimeters and a radius of 18 centimeters. What is its volume?

A researcher examines 27 water samples for iron concentration. The mean iron concentration for the sample data is 0.802 cc/cubic

Delvig [45]

Answer:

90% confidence interval for the population mean iron concentration is [0.771 , 0.832].

Step-by-step explanation:

We are given that a researcher examines 27 water samples for iron concentration. The mean iron concentration for the sample data is 0.802 cc/cubic meter with a standard deviation of 0.093.

Firstly, the pivotal quantity for 90% confidence interval for the population mean iron concentration is given by;

P.Q. = $\frac{\bar X - \mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean iron concentration = 0.802 cc/cubic meter

s = sample standard deviation = 0.093

n = number of water samples = 27

$\mu$ = population mean

Here for constructing 90% confidence interval we have used t statistics because we don't know about population standard deviation.

So, 90% confidence interval for the population mean, $\mu$ is ;

P(-1.706 < $t_2_6$ < 1.706) = 0.90 {As the critical value of t at 26 degree of

freedom are -1.706 & 1.706 with P = 5%}

P(-1.706 < $\frac{\bar X - \mu}{\frac{s}{\sqrt{n} } }$ < 1.706) = 0.90

P( $-1.706 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X - \mu}$ < $1.706 \times {\frac{s}{\sqrt{n} } }$ ) = 0.90

P( $\bar X -1.706 \times {\frac{s}{\sqrt{n} }$ < $\mu$ < $\bar X +1.706 \times {\frac{s}{\sqrt{n} }$ ) = 0.90

90% confidence interval for $\mu$ = [ $\bar X -1.706 \times {\frac{s}{\sqrt{n} }$ , $\bar X +1.706 \times {\frac{s}{\sqrt{n} }$ ]

= [ $0.802 -1.706 \times {\frac{0.093}{\sqrt{27} }$ , $0.802 +1.706 \times {\frac{0.093}{\sqrt{27} }$ ]

= [0.771 , 0.832]

Therefore, 90% confidence interval for the population mean iron concentration is [0.771 , 0.832].

4 0

3 years ago

NEED HELP BADLY !!!!

tatyana61 [14]

Answer:

Part A: Rewrite the expression by factoring out the greatest common factor. (4 points)

answer:

2y(x³+4x-2x²-8)

Part B: Factor the entire expression completely. Show the steps of your work. (6 points)

answer:

2y(x³+4x-2x²-8)

2y(x³-2x²+4x-8)

2y(x²(x-2)+4(x-2))

2y(x²+4)(x-2)

7 0

3 years ago

Write this in order: (greatest to least:) 112 , 100.789 , 101.89 , 101.9 , 190. 1

ruslelena [56]

Answer:

190.1, 101.89, 101.9, 100.789, 112, 1

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

What would the unit rates be for a person who jogged 500 meters in 4 minutes?

kozerog [31]

500 meters/4 minutes = 125 meters/minute

4 minutes / 500 meters = 0.008 minutes/meter

4 0

4 years ago

What is the distance between A (-4,2) and B (12,4)

My name is Ann [436]

$\bf ~~~~~~~~~~~~\textit{distance between 2 points}
\\\\
A(\stackrel{x_1}{-4}~,~\stackrel{y_1}{2})\qquad
B(\stackrel{x_2}{12}~,~\stackrel{y_2}{4})\qquad \qquad
d = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2}
\\\\\\
AB=\sqrt{[12-(-14)]^2+[4-2]^2}\implies AB=\sqrt{(12+14)^2+(4-2)^2}
\\\\\\
AB=\sqrt{26^2+2^2}\implies AB=\sqrt{680}$

3 0

3 years ago

Read 2 more answers