Lee bought a 7 kilogram can of raisins for $6.50. What is the unit price? Round answrr to the nearest cent.

Ratling [72]

Multiply 20 by 5 and you get 100, please tell if this is what you wanted!

8 0

3 years ago

A phycologist is interested in determining the proportion of algae samples from a local rivulet that belong to a particular phyl

LuckyWell [14K]

Answer:

A sample of 16577 is required.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the z-score that has a p-value of $1 - \frac{\alpha}{2}$ .

The margin of error is of:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

99% confidence level

So $\alpha = 0.01$ , z is the value of Z that has a p-value of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

She wants to estimate the proportion using a 99% confidence interval with a margin of error of at most 0.01. How large a sample size would be required?

We have no estimation for the proportion, and thus we use $\pi = 0.5$ , which is when the largest sample size will be needed.

The sample size is n for which M = 0.01. So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.01 = 2.575\sqrt{\frac{0.5*0.5}{n}}$

$0.01\sqrt{n} = 2.575*0.5$

$\sqrt{n} = \frac{2.575*0.5}{0.01}$

$(\sqrt{n})^2 = (\frac{2.575*0.5}{0.01})^2$

$n = 16576.6$

Rounding up:

A sample of 16577 is required.

8 0

3 years ago

An ice cream cone has a height of 4 in and a radius of 1 in. If the cone is 0.1 in thick, what is the difference (in in3) betwee

SSSSS [86.1K]

Answer:

$0.79 in^3$

Step-by-step explanation:

Given data for the cone

height h= 4 in

radius r= 1 in

hence diameter d= 2 in

thickness of cone= 0.1 in

The volume of the cone including the shell can be expressed as

$volume=\frac{1}{3} \pi r^2h$

$volume= \frac{1}{3}*3.142*1^2*4\\\volume= \frac{12.568}{3} \\\volume= 4.189 in^3$

The volume of the ice cream can be expressed as

N/B: the diameter of the ice cream is

2-(0.1*2)= 2-0.2= 1.8 in

hence the radius is 0.9 in

$volume= \frac{1}{3}*3.142*0.9^2*4\\\ volume= \frac{10.18}{3} \\\ volume= 3.39 in^3$

The difference in volume is $4.189-3.39= 0.79 in^3$

8 0

3 years ago

What is the solution of the equation √2x-3-3=6? A) 42 B) 39 C) 3 D) 6

Firlakuza [10]

Answer:

42

Step-by-step explanation:

√2x-3-3=6

√2x-3=6+3

√2x-3=9

2x-3=9^2

2x=81+3

X=84/2

X=42

So value of X is 42

4 0

3 years ago

The table represents the height of a ball thrown up from the roof of a building, h(t), in meters, t seconds after it is thrown u

Anna [14]

• The ball is at the same height as the building between 8 and 10 seconds after it is thrown. TRUE - the height is zero somewhere in that interval, hence the ball is the same height from which it was thrown, the height of the roof of the building.

• The height of the ball decreases and then increases. FALSE - at t=2, the height is greater than at t=0.

• The ball reaches its maximum height about 4 seconds after it is thrown. TRUE - the largest number in the table corresponds to t=4.

• The ball hits the ground between 8 and 10 seconds after it is thrown. FALSE - see statement 1.

• The height of the building is 81.6 meters. FALSE - the maximum height above the building is 81.6 meters. Since the ball continues its travel to a distance 225.6 meters below the roof of the building, the building is at least that high.

1. TRUE
2. False
3. TRUE
4. False
5. False

9 0

3 years ago

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