Solve the system of equations.

How much must be added to each of the three numbers 1, 11, and 23 so that together they form a geometric progression?

Sliva [168]

Answer:

49

Step-by-step explanation:

Let x be unknown number which should be added to numbers 1, 11, 23 to get geometric progression. Then numbers 1 + x, 11 + x, 23 + x are first three terms of geometric progression.

Hence,

$b_1=1+x\\ \\b_2=11+x\\ \\b_3=23+x$

and

$b_2=b_1\cdot q\Rightarrow 11+x=(1+x)q\\ \\b_3=b_2\cdot q\Rightarrow 23+x=(11+x)q$

Express q:

$q=\dfrac{11+x}{1+x}=\dfrac{23+x}{11+x}$

Solve this equation. Cross multiply:

$(11+x)^2=(1+x)(23+x)\\ \\121+22x+x^2=23+x+23x+x^2\\ \\121+22x=23+24x\\ \\22x-24x=23-121\\ \\-2x=-98\\ \\2x=98\\ \\x=49$

5 0

3 years ago

How to reduce into simpler terms.?

Sveta_85 [38]

Answer:

The simplest form of the fraction $\frac{45}{100}$ is $\frac{9}{20}$ .

i.e.

$\frac{45}{100}=\frac{9}{20}$

Step-by-step explanation:

Here are some simple observations regarding how to reduce a fraction into simpler terms:

A fraction is reduced to lowest or simplest terms by finding an equivalent fraction in which the numerator and denominator are as small as possible.

In order to reduce a fraction to lowest or simplest terms, divide the numerator and denominator by their (GCF). Note that (GCF) is also called Greatest Common Factor .

So, lets take a sample fraction and reduce into simpler terms.

Considering the fraction

$\frac{45}{100}$

$\mathrm{Find\:a\:common\:factor\:of\:}45\mathrm{\:and\:}100\mathrm{\:in\:order\:to\:cancel\:it\:out}$

$\mathrm{Greatest\:Common\:Divisor\:of\:}45,\:100:\quad 5$

$\mathrm{Factor\:out\:}5\mathrm{\:from\:the\:numerator\:and\:the\:denominator}$

$45=5\cdot \:9\mathrm{,\:\quad }100=5\cdot \:20$

so

$\frac{45}{100}=\frac{5\cdot \:\:9}{5\cdot \:\:20}$

$\mathrm{Cancel\:the\:common\:factor:}\:5$

$=\frac{9}{20}$

Therefore, the simplest form of the fraction $\frac{45}{100}$ is $\frac{9}{20}$ .

i.e.

$\frac{45}{100}=\frac{9}{20}$

4 0

3 years ago

There are (4^9)^5 ⋅ 4^0 books at the library. What is the total number of books at the library?

Sidana [21]

$(4^9)^5 \cdot 4^0=4^{9*5} \cdot 1=4^{45}$

3 0

3 years ago

The head of maintenance at XYZ Rent-A-Car believes that the mean number of miles between services is 3639 3639 miles, with a var

Andrei [34K]

Answer:

96.6% probability that the mean of a sample would differ from the population mean by less than 126 miles

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

A reminder is that the standard deviation is the square root of the variance.

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this question:

$\mu = 3639, \sigma = \sqrt{145161} = 381, n = 41, s = \frac{381}{\sqrt{41}} = 59.5$

Probability that the mean of the sample would differ from the population mean by less than 126 miles

This is the pvalue of Z when X = 3639 + 126 = 3765 subtracted by the pvalue of Z when X = 3639 - 126 = 3513. So

X = 3765

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{3765 - 3639}{59.5}$

$Z = 2.12$

$Z = 2.12$ has a pvalue of 0.983

X = 3513

$Z = \frac{X - \mu}{s}$

$Z = \frac{3513 - 3639}{59.5}$

$Z = -2.12$

$Z = -2.12$ has a pvalue of 0.017

0.983 - 0.017 = 0.966

96.6% probability that the mean of a sample would differ from the population mean by less than 126 miles

3 0

3 years ago

In ΔOPQ, o = 58 cm, q = 13 cm and ∠Q=52°. Find all possible values of ∠O, to the nearest degree.

PSYCHO15rus [73]

Answer:

There is no possible triangles

Step-by-step explanation:

\frac{\sin A}{a}=\frac{\sin B}{b}

a

sinA

=

b

sinB

From the reference sheet (reciprocal version).

\frac{\sin O}{58}=\frac{\sin 52}{13}

58

sinO

=

13

sin52

Plug in values.

\sin O=\frac{58\sin 52}{13}\approx 3.5157403

sinO=

13

58sin52

≈3.5157403O=\sin^{-1}(3.5157403)= \text{ERROR}

O=sin

−1

(3.5157403)=ERROR

Sine cannot be greater than 1.

{No Possible Triangles}

No Possible Triangles

{}

7 0

3 years ago