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3 years ago

What is the sum of the geometric series 20 + 21 + 22 + 23 + 24 + … + 29?

Mathematics

2 answers:

aliya0001 [1]3 years ago

7 0

There are no answer is right !

alekssr [168]3 years ago

5 0

Answer:

The answer is a) 1,023

Step-by-step explanation:

A geometric series is a series with a constant ratio between successive terms. So, the given series must be in the exponential form.

$2^{0}+2^{1}+2^{2}+2^{3}+2^{4}+2^{5}+2^{6}+2^{7}+2^{8}+2^{9}$

We have been asked about the sum of the geometric series :

$1+2+8+16+32+64+128+256+512$

Sum = 1023

Hence, option A is the answer.

<h2><u>If Solving the series as it is given:</u></h2>

The given series : 20+21+22+23+....+29 is an arithmetic series.

Its sum is : $\frac{10(20+29)}{2}=245$

I have solved the question both ways. Both the answers are right with respect to the series name.

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You stand 100’ from the base of a tower. The tower is 1,058’ tall. What is the angle from where you are standing to the top of t

hodyreva [135]

Answer: 85°

Step-by-step explanation:

Trig functions are remembered by

SOD CAD TOA,

sin = opposite / distance, cos = adjacent / distance, and tan = opposite / adjacent.

Here we have the adjacent side = 100, opposite side = 1058. The tower would fall over if it weren't vertical, and we assume the area is flat and level. So tangent of the answer is 10.58.

We need the angle whose tangent is 10.58.

On Android calculator you swipe left to get the trig functions, tap INV, if RAD is showing tap it to change it to DEG, and tap tan⁻¹. Swipe right and you see tan⁻¹(. Enter 10.58 and the result shows 84.6005606. If it shows 1.47655833 tap the RAD in upper left to change to DEG.

8 0

3 years ago

What number has the same value as 12 tens?

Sergio [31]

1,200, this is because 12 time 10 is 1,200

4 0

3 years ago

Read 2 more answers

Find the least number that must be subtracted from 21 2o show the result is a perfect square

ivanzaharov [21]

Answer:

Step-by-step explanation:

2 × 2 = 4

3× 3 = 9

4 × 4 =16

5 × 5 =25

16 is the only number and closest number to 21 to subtract from

5 0

2 years ago

Identify whether the change represent growth or decay and determine the percentage rate increase or decrease in y= 16(1.059)^z

AnnyKZ [126]

Answer: Growth rate of 5.9%

Step-by-step explanation:

Since 1.059>1, it represents <u>growth</u>.

$1+r=1.059 \\ \\ r=0.059=\boxed{5.9\%}$

5 0

1 year ago

A sports marketing company is interested in how many hours teenagers in a town spend watching sports. They randomly select 40 te

garri49 [273]

Answer:

(5.097, 7.404)

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 40 - 1 = 39

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 39 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.9}{2} = 0.95$ . So we have T = 1.6849

The margin of error is:

$M = T\frac{s}{\sqrt{n}} = 1.6849\frac{4.33}{\sqrt{40}} = 1.154$

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 6.25 - 1.154 = 5.096 hours

The upper end of the interval is the sample mean added to M. So it is 6.25 + 1.154 = 7.404 hours.

The answer is (5.097, 7.404)

5 0

3 years ago