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4 years ago

Proportions - if 1 subscription costs $21, how much is 28 subscriptions?

1 answer:

6 0

1 subscription = $21
28 subscriptions = x
You know 1 subscription is $21
You want to find out how much 28 subscriptions are
Multiply 28 (subscriptions) by 21 ($ per subscription)
28 x 21 = 588
28 subscriptions cost $588
If you would like the formula to find out how many subscriptions cost hat amount of money,
21x = y
x is how many subscriptions you want, while y is the total cost of the money

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The circumference of the base of the cone is 8.51 inches. What is the volume of the cone in terms of 1? Round to the nearest hun

andre [41]

Answer

14.212444625

Step-by-step explanation:

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3 years ago

A participant in a medical study walked 11,567 steps per day. If their steps are 2.5 feet per step, how many kilometers would th

Paladinen [302]

Answer:

Approximately 61.7 kilometers in a week

Step-by-step explanation:

11567 steps/day x 7 days/week x 2.5 feet/step x 1 kilometer/3280 feet = 61.7

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3 years ago

A, B and C are events such that P(A) = 1/3, P(B) = ¼, and P(C) = 1/5. Find P(AUBUC) under each of the following assumptions: a)

marta [7]

(a) If $A,B,C$ are mutually exclusive, then

$P(A\cap B)=P(A\cap C)=P(B\cap C)=P(A\cap B\cap C)=0$

so we have

$P(A\cup B\cup C)=P(A)+P(B)+P(C)=\dfrac{47}{60}$

(b) If $A,B,C$ are mutually independent, then

$P(A\cap B)=P(A)P(B),$

$P(A\cap C)=P(A)P(C),$

$P(B\cap C)=P(B)P(C),$

$P(A\cap B\cap C)=P(A)P(B)P(C)$

so that

$P(A\cup B\cup C)=P(A)+P(B)+P(C)-(P(A\cap B)+P(A\cap B)+P(B\cap C))+P(A\cap B\cap C)$

$P(A\cup B\cup C)=\dfrac{47}{60}-\left(\dfrac1{12}+\dfrac1{15}+\dfrac1{20}\right)+\dfrac1{60}$

$P(A\cup B\cup C)=\dfrac35$

5 0

3 years ago

A bond analyst is analyzing the interest rates for equivalent municipal bonds issued by Georgia and Ohio. A sample of 60 bonds i

slavikrds [6]

Answer:

Since our calculated value is outside than our critical value, $z_{calc}=-136.438$ , we have enough evidence to reject the null hypothesis at 5% of significance. So there is not nough evidence to conclude that mean for Ohio it's significantly different than the mean for Georgia.

Step-by-step explanation:

1) Data given and notation

$\bar X_{1}=3.6$ represent the mean for Georgia

$\bar X_{2}=4.15$ represent the mean for Ohio

$s_{1}=0.03$ represent the population standard deviation for Georgia

$\sigma_{2}=0.01$ represent the population standard deviation for Ohio

$n_{1}=60$ sample size for Georgia

$n_{2}=80$ sample size for Ohio

z would represent the statistic (variable of interest)

$p_v$ represent the p value

2) Concepts and formulas to use

We need to conduct a hypothesis in order to check if the means are different for both groups, the system of hypothesis would be:

H0: $\mu_{1} = \mu_{2}$

H1: $\mu_{1} \neq \mu_{2}$

If we analyze the size for the samples both are higher than 30, we can assume that the normal distribution is the correct disirbution for the statistic, so for this case is better apply a z test to compare means, and the statistic is given by:

$z=\frac{\bar X_{1}-\bar X_{2}}{\sqrt{\frac{\sigma^2_{1}}{n_{1}}+\frac{\sigma^2_{2}}{n_{2}}}}$ (1)

z-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

3) Calculate the statistic

We have all in order to replace in formula (1) like this:

$z=\frac{3.6-4.15}{\sqrt{\frac{0.03^2}{60}+\frac{0.01^2}{80}}}=-136.438$

4) Find the critical value

In order to find the critical value we need to take in count that we are conducting a two tailed test, so we are looking on the normal standard distribution a value that accumulates 0.025 of the area on the right and 0.975 of the area on the left. We can us excel or a table to find it, for example the code in Excel is:

"=NORM.INV(1-0.025,0,1)", and we got $z_{critical}=\pm 1.96$

5) Statistical decision

Since our calculated value is outside than our critical value, $z_{calc}=-136.438$ , and outside of (-1.96,1.96), we have enough evidence to reject the null hypothesis at 5% of significance. So there is not nough evidence to conclude that mean for Ohio it's significantly different than the mean for Georgia.

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3 years ago

There is a bag filled with 4 blue, 3 red and 5 green marbles. A marble is taken at random from the bag, the colour is noted and

zalisa [80]

Answer:

The answer would be just about 61% or 9/14

Step-by-step explanation:

So, it would be a 71% chance to get 1 green out of the bag, but then you have to keep that green out, which then lowers the chances of getting another green out of the bag, then you have to combine the percentages, and then that is the final percentage.

3 0

3 years ago