Alex, Mark & Peter share some money in the ratio 4 : 7 : 1. In total, Alex and Peter receive £60. How much does Mark get?

A plate moves south at a rate of 2 cm/year. How many meters south from its original location will the plate be in 4,000 years?

Neporo4naja [7]

Answer:

I hope I can help

welcome po

3 0

2 years ago

Read 2 more answers

Mikela claims that the sum of any two numbers is greater than the larger of the two numbers. Jim claims that the sum of any two

qaws [65]

<u>ANSWER: </u>

The statement of Jim is correct

<u>SOLUTION: </u>

Given statements are

Mikela claims that sum of any two numbers is greater than the larger of the two numbers.

Jim claims that the sum of any two natural numbers is greater than the larger of the two numbers.

Let a,b be the two numbers and a is the greatest of a and b

According to the mikela statement = a + b > a

b > a – a

b > 0

Here, we got an condition that b > 0, but it may not be true always.

Above condition fails when b is either 0 or negative number.

Jim - sum of any two natural numbers is greater than the larger of the two numbers.

Let a,b be the two natural numbers. And a is the greatest of a and b

According to the jim statement = a + b > a

b > a – a

b > 0

Here, we got an condition that b > 0,

And this statement will always be true because b is an natural number, so it will be greater than 0.

Hence jim’s statement is true.

8 0

2 years ago

Which is more economical: purchasing the economy size of a detergent at 7 kilograms for $7.15 or purchasing the regular size a

Kruka [31]

Regular size saves $0.0003 per gram I think
someone pls fact check me

8 0

2 years ago

From Statistics and Data Analysis from Elementary to Intermediate by Tamhane and Dunlop, pg 265. A thermostat used in an electri

Leviafan [203]

Answer:

$t=\frac{201.77-200}{\frac{2.41}{\sqrt{10}}}=2.32$

The degrees of freedom are given by:

$df=n-1=10-1=9$

The p value for this case is given by:

$p_v =2*P(t_{(9)}>2.32)=0.0455$

For this case since the p value is lower than the significance level we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly different from 200 F.

Step-by-step explanation:

Information given

data: 202.2 203.4 200.5 202.5 206.3 198.0 203.7 200.8 201.3 199.0

We can calculate the sample mean and deviation with the following formulas:

$\bar X= \frac{\sum_{i=1}^n X_i}{n}$

$\sigma=\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

$\bar X=201.77$ represent the sample mean

$s=2.41$ represent the sample standard deviation

$n=10$ sample size

$\mu_o =200$ represent the value that we want to test

$\alpha=0.05$ represent the significance level for the hypothesis test.

t would represent the statistic

$p_v$ represent the p value for the test

Hypothesis to test

We want to determine if the true mean is equal to 200, the system of hypothesis are :

Null hypothesis: $\mu = 200$

Alternative hypothesis: $\mu = 200$

The statistic for this case is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

The statistic is given by:

$t=\frac{201.77-200}{\frac{2.41}{\sqrt{10}}}=2.32$

The degrees of freedom are given by:

$df=n-1=10-1=9$

The p value for this case is given by:

$p_v =2*P(t_{(9)}>2.32)=0.0455$

For this case since the p value is lower than the significance level we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly different from 200 F.

4 0

2 years ago

Maxis taking a cross-country road trip. Gas prices vary as the friends travel across the US from $4 dollars per gallon on the ea

Zolol [24]

Answer:

A) The amount of gas they bought on each coast;

East Coast = 35 gallons

Mid-US = 100 gallons

West Coast = 15 gallons

B) The amount of gas they bought on each coast on the return journey;

East Coast = 37 gallons

Mid-US = 116 gallons

West Coast = 21 gallons

Step-by-step explanation:

Complete Question

Maxis taking a cross-country road trip. Gas prices vary as the friends travel across the US from $4 dollars per gallon on the east coast to $3 in the mid-US, to $5 on the west coast.

(a) If they used twice as much gas in the mid-US than on either coast combined, and they spend $515 on gas to purchased 150 gallons of gas, how many gallons of gas did they buy at each price?

The answer to this question is East Coast - 35 gal, Mid-US - 100 gal, West Coast - 15 gal.

(b) On their way back they had more baggage in the car and spend $601 for 174 gallons of gas. Based on the same ratio as in Part (a), how many gallons of gas did they buy at each price? I don't know the answer to this one

Solution

Let the amount of fuel bought on the east coast = x gallons

Let the amount of fuel bought on the mid-coast = y gallons

Let the amount of fuel bought on the west coast = z gallons

a) - They used twice as much gas in the mid-US than on either coast combined

y = 2(x + z) = 2x + 2z (eqn 1)

- They spend $515 on gas to purchase 150 gallons of gas.

Total gallons purchased = x + y + z = 150

Total amount spent = 4x + 3y + 5z = 515

From eqn 1, y = 2x + 2z, inserting this value for y in the 2 other equations

x + y + z = x + 2x + 2z + z = 150

3x + 3z = 150

Divide through by 3

x + z = 50 (eqn *)

4x + 3y + 5z = 4x + 3(2x + 2z) + 5z = 515

4x + 6x + 6z + 5z = 515

10x + 11z = 515 (eqn **)

x + z = 50

10x + 11z = 515

Solving the simultaneous equation,

x = 35 gallons

z = 15 gallons

y = 2x + 2z = 2(35 + 15) = 100 gallons

B) On the return journey, the ratio between x, y and z is still the same, but the total gallons and total amount spent is now different.

They used twice as much gas in the mid-US than on either coast combined

y = 2(x + z) = 2x + 2z (eqn 1)

- They spend $601 on gas to purchase 174 gallons of gas.

Total gallons purchased = x + y + z = 174

Total amount spent = 4x + 3y + 5z = 601

From eqn 1, y = 2x + 2z, inserting this value for y in the 2 other equations

x + y + z = x + 2x + 2z + z = 174

3x + 3z = 174

Divide through by 3

x + z = 58 (eqn *)

4x + 3y + 5z = 4x + 3(2x + 2z) + 5z = 601

4x + 6x + 6z + 5z = 601

10x + 11z = 601 (eqn **)

x + z = 58

10x + 11z = 601

Solving the simultaneous equation,

x = 37 gallons

z = 21 gallons

y = 2x + 2z = 2(37 + 21) = 116 gallons

Hope this Helps!!!

5 0

2 years ago