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3 years ago

PLEASE HELP ASAP!!! CORRECT ANSWER ONLY PLEASE!!! I CANNOT RETAKE THIS!!

Mathematics

1 answer:

kipiarov [429]3 years ago

6 0

$T(t) = T_s + (T_0 - T_s)e^{-kt}$

$T(t) - T_s = (T_0 - T_s)e^{-kt}$

$\dfrac{ T(t) - T_s}{T_0 - T_s} = e^{-kt}$

$\ln \dfrac{ T(t) - T_s}{T_0 - T_s} = -kt$

$k = - \dfrac{ \ln \dfrac{ T(t) - T_s}{T_0 - T_s} }{t}$

OK now let's plug in the numbers.

We have t=15 minutes, T_0 = 80 C, Ts = 50, T(15)=60 C,

$k = - \dfrac{ \ln \dfrac{ 60 - 50}{80 - 50} }{15 \textrm{ min}}$

$k = - \frac{1}{15} \ln \frac 1 3$

$k = \frac{1}{15} \ln 3$

$k \approx 0.07324$ per minute

Answer: B

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alexandr402 [8]

Answer:

The length of FG is 2.

Step-by-step explanation: B and F are the same point, just reflected, so BC=FG.

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3 years ago

PLZZZ HELP FOR BRAINLIST

lina2011 [118]

Answer:

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Step-by-step explanation:

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3 years ago

The average hourly charge of plumbers in the Denver area is $84.00 with a standard deviation of $4.00. Assume that the hourly ch

Simora [160]

Answer:

The probability is 0.31

Step-by-step explanation:

In this question, we are tasked with calculating the probability that a random plumber called at Denver will charge an amount greater than $86 given the mean and the standard deviation.

Firstly, we calculate the standard score of $86 using the mean and the standard deviation.

Mathematically;

z-score = (x-mean)/SD

where x = 86, mean = 84 and SD = 4

z-score = (86-84)/4 = 2/4 = 0.5

Hence, we want to calculate P(z ≥ 0.5)

Using standard table

P( (z ≥ 0.5) = 1 - P(z ≤ 0.5) = 1 - ( 0.19146 + 0.5) = 0.30854

To the nearest hundredth = 0.31

5 0

3 years ago

Aria paid $75,000 for her house. Its property value increased by 2.2% per year. When Aria sold her house after eleven years, how

astra-53 [7]

Answer:

When Aria sold her house after eleven years it worth was <u>$95,300</u>.

Step-by-step explanation:

Given:

Aria paid $75,000 for her house. Its property value increased by 2.2% per year.

Now, to find the worth of Aria house when sold after eleven years.

Let the amount of house after eleven years be $x.$

Amount Aria paid for her house (A) = $75,000.

Rate of property increased per year (r) = 2.2%.

Time (t) = 11 years.

Now, to get the amount of house after eleven years we put formula:

$x=A\times (1+\frac{r}{100})^{11}$

$x=75000\times (1+\frac{2.2}{100})^{11}$

$x=75000\times (1+0.022)^{11}$

$x=75000\times (1.022)^{11}$

$x=75000\times 1.2704$

$x=95280.$

<em>The amount of house after eleven years to the nearest hundred dollars is $95,300.</em>

Therefore, when Aria sold her house after eleven years it worth was $95,300.

3 0

3 years ago

Minny has two coupons, but can use one of them. The first one is for $5 off an item; the second coupon is for 20% off an item. T

joja [24]

Let's first solve for the $5 off coupon,

$28 - 5 = 23$

The final total is $23.00 with $5 off.

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Now for the final price of the 20% off coupon,

$20\% = 0.2$

0.2 or 0.20 is decimal form of 20%. Easier to multiply than in percent form!

$0.2 \times 28 = 5.6$

$5.6 or $5.60 is 20% of 28, we're not done yet!

Lastly, subtract 20% off of 28 (5.6) from 28,

$28 - 5.6 = 22.4$
$22.4 or $22.40 is the final after 20% off!

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Q. Which is less after the discounts??

$23.00 or $22.40

A. $22.40 of course which was the 20% off.

Part A : Which coupon should she use ?

Answer : Well, to get a lower price, less to pay, the 20% off coupon is better!

Part B: How much money will she save by using the better coupon?

Answer : $5.6 / $5.60 is the amount she'll save!

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I hope that helps you out!!

Any more questions, please just ask me!!

~ Zoey

5 0

3 years ago