What's x value 1/2x=1/3

makvit [3.9K]

Is a number negative

5 0

4 years ago

Barbara has $70.00 in her pocket and a $20 gift card. Which purchase will she be able to make without having to use her credit c

suter [353]

Yes depending on her purchase. If it is over 90.00 dollars then no she will not.

3 0

4 years ago

Three water storage containers have the same volume in the shape of a cylinder, a cone, and a sphere. The base radius of the cyl

fredd [130]

Answer:

- The ratio of the height of the cone to the height of the cylinder is 3:1

- The ratio of the height of the cone to radius of the sphere is 4:1

Step-by-step explanation:

Note that the radii of all the structures are the same.

Let the height of the cone be H and the height of the cylinder be h

The volume of each of the shapes are given below as

Volume of cylinder = πr²h

Volume of a cone = (1/3)πr²H

Volume of a sphere = (4/3)πr³

1) The ratio of the height of the cone to the height of the cylinder

To obtain this, we equate the volume of those two structures

Volume of the cone = Volume of the cylinder

(1/3)πr²H = πr²h

πr² cancels out on both sides and we're left with

(H/3) = h

H = 3h

(H/h) = (3/1)

So, The ratio of the height of the cone to the height of the cylinder is 3:1

2) The ratio of the height of the cone to radius of the sphere

Similarly equating the volumes of the cone and the sphere

(1/3)πr²H = (4/3)πr³

(1/3)πr² cancels out on both sides and we're left with

H = 4r

(H/r) = (4/1)

The ratio of the height of the cone to radius of the sphere is 4:1

Hope this Helps!!!

8 0

4 years ago

A class has 10 boys and 12 girls. in how many ways can a committee of four be selected if the committee can have at most two gir

V125BC [204]

C(12,0)C(10,4)+C(12,1)C(10,3)+C(12,2)C(10,2) = (1)(210)+(12)(120)+(66)(45) = 210+1440+2904 = 4554 Answeer: 4554 ways

5 0

4 years ago

Professor Doom has applied to the town planning board to build a Villain's Lair in a suburban neighborhood. The local residents

tester [92]

Answer:

Check explanation below.

Step-by-step explanation:

Hello!

The objective of this experiment is to test if doctor Doom is controlling the neighbors' minds from his new Lair. To test this a random sample of 11 neighbors was taken and a "free will" test was administrated before the Villain's Lair was constructed and again after it was finished.

This experiment type where you have a single sample and the variable is measured "before" and "after" applying a treatment (in this case, that doctor Doom has moved into town) is a classic example of a paired sample test. You have two dependent variables, X₁: "Results of the free will test before Dr. Doom Lair is constructed" and X₂: "Results of the free will test after Dr. Doom Lair is constructed", with these variables you can establish a new variable, Xd, that I'll define as " X₁- X₂", and the objective of my hypothesis test will be to know if there is any change after the Lair is done, if there is, in fact, a change then the population mean of the difference will be nonzero, symbolically: μd ≠ 0

Using the data I've calculated the summary measures for Xd:

sample mean: Xd[bar]= 3.18

sample standard deviation: Sd= 5.44

The statistic hypothesis is:

H₀: μd = 0

H₁: μd ≠ 0

α: 0.05

(There is no signification level specified, so I've chosen the most common one)

Assuming that the variable difference, Xd, has a normal distribution, and with unknown population variance, the best statistic to use is the Students-t for paired samples:

t= Xd[bar] - μd ~t $_{n-1}$

Sd/√n

This test is two-tailed, so you will reject at low values of the statistic or at high values of it.

$t_{n-1;\alpha/2 } = t_{10; 0.025} = -2.228$

$t_{n-1; 1-\alpha /2} = t_{10; 0.975} = 2.228$

If t ≤ -2.228 or t ≥ 2.228 then you reject the null hypothesis.

If -2.228 < t < 2.228 then you don't reject the null hypothesis.

t= Xd[bar] - μd = 3.18 - 0 = 1.94

Sd/√n 5.44/√11

Since the statistic value t= 1.94 then the decision is to not reject the null hypothesis.

So, with a significance level of 5% there is not enough evidence to reject the null hypothesis, this means that the population mean of the difference on the free will test results of the neighbors before and after the Villain's Lair was constructed is equal to cero. In other words, there is not enough evidence to conclude that Dr. Doom is controlling the neighbor's minds.

I hope it helps!

3 0

3 years ago