Id : 688 737 6744<br>pas : c8SNRa<br>❤❤<br>

Lars deposited $50 into a savings account for which interest is compounded quarterly. According to the rule of 72, what interest

Ivanshal [37]

Answer: C 2.5%

Step-by-step explanation:

The "Rule of 72" is a easy way to calculate how much time an investment will take to double with a given fixed annual rate of interest.

Just we have to divide 72 by the annual rate of return(r), we can get a rough estimate of how many years it will take to double the initial investment .

Now, in given problem: Let 'r' be the rate of interest

Time to double the amount=29 years

Thus by rule 72 ,

$\frac{72}{r}=29\\\Rightarrow\ r=\frac{72}{29}=2.4827\%\approx2.5\%$

Therefore, C is the right option.

3 0

3 years ago

Read 2 more answers

QUESTION IN THE ATTACHMENT

eimsori [14]

Answer:

A. The sum of the first 10th term is 100.

B. The sum of the nth term is n²

Step-by-step explanation:

Data obtained from the question include:

Sum of 20th term (S20) = 400

Sum of 40th term (S40) = 1600

Sum of 10th term (S10) =..?

Sum of nth term (Sn) =..?

Recall:

Sn = n/2[2a + (n – 1)d]

Sn is the sum of the nth term.

n is the number of term.

a is the first term.

d is the common difference

We'll begin by calculating the first term and the common difference. This is illustrated below:

Sn = n/2 [2a + (n – 1)d]

S20 = 20/2 [2a + (20 – 1)d]

S20= 10 [2a + 19d]

S20 = 20a + 190d

But:

S20 = 400

400 = 20a + 190d .......(1)

S40 = 40/2 [2a + (40 – 1)d]

S40 = 20 [2a + 39d]

S40 = 40a + 780d

But

S40 = 1600

1600 = 40a + 780d....... (2)

400 = 20a + 190d .......(1)

1600 = 40a + 780d....... (2)

Solve by elimination method

Multiply equation 1 by 40 and multiply equation 2 by 20 as shown below:

40 x equation 1:

40 x (400 = 20a + 190d)

16000 = 800a + 7600. ........ (3)

20 x equation 2:

20 x (1600 = 40a + 780d)

32000 = 800a + 15600d......... (4)

Subtract equation 3 from equation 4

Equation 4 – Equation 3

32000 = 800a + 15600d

– 16000 = 800a + 7600d

16000 = 8000d

Divide both side by 8000

d = 16000/8000

d = 2

Substituting the value of d into equation 1

400 = 20a + 190d

d = 2

400 = 20a + (190 x 2)

400 = 20a + 380

Collect like terms

400 – 380 = 20a

20 = 20a

Divide both side by 20

a = 20/20

a = 1

Therefore,

First term (a) = 1.

Common difference (d) = 2.

A. Determination of the sum of the 10th term.

First term (a) = 1.

Common difference (d) = 2

Number of term (n) = 10

Sum of 10th term (S10) =..?

Sn = n/2 [2a + (n – 1)d]

S10 = 10/2 [2x1 + (10 – 1)2]

S10 = 5 [2 + 9x2]

S10 = 5 [2 + 18]

S10 = 5 x 20

S10 = 100

Therefore, the sum of the first 10th term is 100.

B. Determination of the sum of the nth term.

First term (a) = 1.

Common difference (d) = 2

Sum of nth term (Sn) =..?

Sn = n/2 [2a + (n – 1)d]

Sn = n/2 [2x1 + (n – 1)2]

Sn = n/2 [2 + 2n – 2]

Sn = n/2 [2 – 2 + 2n ]

Sn = n/2 [ 2n ]

Sn = n²

Therefore, the sum of the nth term is n²

6 0

2 years ago

What is 4 plus 4 hehe

Lynna [10]

Answer:

(plus = +)

-,-

Step-by-step explanation:

<h2>Hope it helps! </h2>

4 0

3 years ago

In how many ways can 10 people form couples of two?

maxonik [38]

Answer:

It should be 10 raised to power 2 which is a hundred.

4 0

2 years ago

A gallup survey indicated that 72% of 18- to 29-year-olds, if given choice, would prefer to start their own business rather than

Neko [114]

Answer:

The probability that no more than 70% would prefer to start their own business is 0.1423.

Step-by-step explanation:

We are given that a Gallup survey indicated that 72% of 18- to 29-year-olds, if given choice, would prefer to start their own business rather than work for someone else.

Let $\hat p$ = <u><em>sample proportion of people who prefer to start their own business</em></u>

The z-score probability distribution for the sample proportion is given by;

Z = $\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ~ N(0,1)

where, p = population proportion who would prefer to start their own business = 72%

n = sample of 18-29 year-olds = 600

Now, the probability that no more than 70% would prefer to start their own business is given by = P( $\hat p$ $\leq$ 70%)

P( $\hat p$ $\leq$ 70%) = P( $\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ $\leq$ $\frac{0.70-0.72}{\sqrt{\frac{0.70(1-0.70)}{600} } }$ ) = P(Z $\leq$ -1.07) = 1 - P(Z < 1.07)

= 1 - 0.8577 = <u>0.1423</u>

The above probability is calculated by looking at the value of x = 1.07 in the z table which has an area of 0.8577.

3 0

3 years ago

Id : 688 737 6744pas : c8SNRa❤❤​

Id : 688 737 6744pas : c8SNRa❤❤