Compound Interest - Precalculus | Mathematics | Page 1

rotund geyser Dec 6, 2024, 4:14 AM

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Please help me finish this. These are my last attempts. I do not know what I am doing wrong.

formal tangleBOT Dec 6, 2024, 4:14 AM

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rotund geyser Please help me finish this. These are my last attempts. I do not know what I am ...

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manic whale Dec 6, 2024, 4:22 AM

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rotund geyser Please help me finish this. These are my last attempts. I do not know what I am ...

Take note it's compounded quarterly

rotund geyser Dec 6, 2024, 4:22 AM

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manic whale Take note it's compounded quarterly

ye 4

manic whale Dec 6, 2024, 4:23 AM

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So how are you calculating the compound interest

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You know the formula yes?

manic whale Dec 6, 2024, 4:25 AM

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rotund geyser Please help me finish this. These are my last attempts. I do not know what I am ...

How are you getting the same answers for 3 years and 7 years

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Can I see your workings

rotund geyser Dec 6, 2024, 4:30 AM

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manic whale How are you getting the same answers for 3 years and 7 years

It's my last attempt, can u tell what you get for 5 and 7 years, please?

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And I used the compound interest formula

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I cant afford to make a mistake ill worth with you once i finish this because my wifi goes out at 12am

manic whale Dec 6, 2024, 4:30 AM

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Yea just show me how you used the formula

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I'll point out your error

rotund geyser Dec 6, 2024, 4:31 AM

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First, 3591.81 for 5 correct?

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and 3853.70 for 7

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I get (3000)(1.197271)

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and (3000)(1.284567)

light igloo Dec 6, 2024, 4:32 AM

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Stop asking to confirm your answers, we're asking you to show your work.

rotund geyser Dec 6, 2024, 4:32 AM

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Alright

light igloo Dec 6, 2024, 4:32 AM

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Because the reason you're getting the wrong answer is because you're making a mistake in your work.

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And teaching you how to do the work correctly will help you way more than telling you the answer to this specific question.

rotund geyser Dec 6, 2024, 4:34 AM

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heres my work for A(7)

light igloo Dec 6, 2024, 4:34 AM

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rotund geyser

Okay, this is just kinda all over the place.

rotund geyser Dec 6, 2024, 4:34 AM

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ik i just dont have the time

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but is the process correct

light igloo Dec 6, 2024, 4:35 AM

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You have half an hour, right?

rotund geyser Dec 6, 2024, 4:35 AM

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yes

light igloo Dec 6, 2024, 4:35 AM

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So just relax and let's use that half an hour.

rotund geyser Dec 6, 2024, 4:35 AM

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okay

light igloo Dec 6, 2024, 4:35 AM

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Okay, so. What's the general form of the compound interest formula?

rotund geyser Dec 6, 2024, 4:35 AM

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A(t)=P(1+ r/n)^nt

light igloo Dec 6, 2024, 4:36 AM

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Okay, so here, what's P?

rotund geyser Dec 6, 2024, 4:36 AM

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3000(1+(0.0375/4)^(4*3)

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3000 is the principal number

light igloo Dec 6, 2024, 4:36 AM

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Okay, please answer the question I asked.

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Right, P = 3000.

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What's r?

rotund geyser Dec 6, 2024, 4:36 AM

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0.0375

light igloo Dec 6, 2024, 4:36 AM

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What's n?

rotund geyser Dec 6, 2024, 4:36 AM

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4

light igloo Dec 6, 2024, 4:37 AM

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Therefore, A(t) = 3000 * (1 + 0.0375/4)^(4t).

rotund geyser Dec 6, 2024, 4:37 AM

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mhm

light igloo Dec 6, 2024, 4:37 AM

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Now, first of all, I think you should just plug this directly into your calculator instead of trying to simplify by like, actually carrying out the division of 0.0375/4 or anything.

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Secondly, when you do, be very mindful of the order of operations. Make sure you have parentheses in place to force your calculator to evaluate the expression in the correct order.

rotund geyser Dec 6, 2024, 4:38 AM

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Okay, I understand this part.

light igloo Dec 6, 2024, 4:38 AM

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light igloo Therefore, `A(t) = 3000 * (1 + 0.0375/4)^(4t)`.

Okay, so first we want A(3), right?

rotund geyser Dec 6, 2024, 4:39 AM

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Nah, A(5).

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It's too late for that one, unfortunately.

light igloo Dec 6, 2024, 4:39 AM

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Okay, A(5).

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So show me exactly what you plan to type into your calculator.

rotund geyser Dec 6, 2024, 4:40 AM

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3000(1+0.009375)^(20)

light igloo Dec 6, 2024, 4:40 AM

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rotund geyser 3000(1+0.009375)^(20)

Wait, explain that middle bit.

rotund geyser Dec 6, 2024, 4:40 AM

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light igloo Wait, explain that middle bit.

Its 0.0375/4.

light igloo Dec 6, 2024, 4:41 AM

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Okay, look.

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Just type 3000 * (1 + 0.0375/4)^(4 * 5).

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Exactly.

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Make your calculator do all the work.

rotund geyser Dec 6, 2024, 4:41 AM

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I get: 3615.53137766

light igloo Dec 6, 2024, 4:41 AM

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rotund geyser I get: 3615.53137766

Okay.

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But just to drive this point home, there is literally no point in doing some of the work for your calculator.

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That just makes it easier to make mistakes.

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When you plug something into a calculator, keep it in a recognizable form, so that you know you're getting all the numbers right.

rotund geyser Dec 6, 2024, 4:43 AM

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To the nearest cent, that's 3,615.53.

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And yes, okay.

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Now for A(7), using your same model, 3000 * (1 + 0.0375/4)^(4 * 7),

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3895.76262744

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3,895.76

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Are these good?

light igloo Dec 6, 2024, 4:44 AM

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They look alright to me.

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And with fifteen minutes to spare.

rotund geyser Dec 6, 2024, 4:46 AM

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You are a life saver

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I just need to slow down and think

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Yeah mb bro if i was rushing you, i got crazy anxiety with school work and my time is bad

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Aint help that i suck ass at math 😭

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Thanks @light igloo

light igloo Dec 6, 2024, 4:47 AM

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rotund geyser Aint help that i suck ass at math 😭

In your defense, I expect that it's more likely your teachers suck at teaching math.

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Like, how much time do they spend proving the things they're telling you?

rotund geyser Dec 6, 2024, 4:48 AM

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+close

hardy meteorBOT Dec 6, 2024, 4:48 AM

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rotund geyser +close

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hardy meteorBOT Dec 6, 2024, 4:48 AM

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hardy meteor

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#Compound Interest - Precalculus