Many people consider their smart phone to be essential! Communication, news, Internet, entertainment, photos, and just keeping current are all conveniently possible with a smart phone. However, the battery better be charged or the phone is useless. Battery life of course depends on the frequency, duration, and type of use. One study involving heavy use of the phones showed the mean of the battery life to be 15.25 hours with a standard deviation of 2.2 hours. Then the battery needs to be recharged. Assume the battery life between charges is normally distributed.

Required:
a. Find the probability that with heavy use, the battery life exceeds 11 hours.
b. You are planning your recharging schedule so that the probability your phone will die is no more than 5%. After how many hours should you plan to recharge your phone?

Answer:

[tex]x=2[/tex]

Step-by-step explanation:

When given the following equation;

[tex]\frac{x+3}{3x-2}-\frac{x-3}{3x+2}=\frac{44}{9x^2-4}[/tex]

One has to solve for the variable (x). Remember, when working with fractions, one must have a common denominator in order to perform operations. Since the denominators on the left side of the equation are unlike, one must change them so that they are like denominators. Multiply each fraction by the other fraction's denominator on the respective side. Remember to multiply both the numerator and denominator by the value to ensure that the equation remains true.

[tex]=\frac{x+3}{3x-2}*(\frac{3x+2}{3x+2})-\frac{x-3}{3x+2}*(\frac{3x-2}{3x-2})=\frac{44}{9x^2-4}[/tex]

Simplify,

[tex]=\frac{(x+3)(3x+2)}{(3x-2)(3x+2)}-\frac{(x-3)(3x-2)}{(3x+2)(3x-2)}=\frac{44}{9x^2-4}\\\\=\frac{3x^2+11x+6}{9x^2-4}-\frac{3x^2-11x+6}{9x^2-4}=\frac{44}{9x^2-4}[/tex]

Distribute the negative sign to simplify the left side of the equation;

[tex]=\frac{3x^2+11x+6}{9x^2-4}-\frac{3x^2-11x+6}{9x^2-4}=\frac{44}{9x^2-4}\\\\=\frac{3x^2+11x+6-(3x^2-11x+6)}{9x^2-4}=\frac{44}{9x^2-4}\\\\=\frac{3x^2+11x+6-3x^2+11x-6}{9x^2-4}=\frac{44}{9x^2-4}\\\\=\frac{22x}{9x^2-4}{=\frac{44}{9x^2-4}[/tex]

Since the denominators on opposite sides of the equation are like, one can now ignore the denominators,

[tex]=22x=44[/tex]

Inverse operations,

[tex]=22x=44[/tex]

   ÷[tex]2[/tex]       ÷[tex]2[/tex]

     [tex]x=2[/tex]

Answer:

Mr. Pinter's class has 42 students, Mrs. Rupert's class has 21 students, and Mrs. Althouse's class has 43 students.

Step-by-step explanation:

This question is solved using a system of equations.

I am going to say that:

Mr. Pinter's class has x students.

Mrs. Rupert's class has y students.

Mrs. Althouse's class has z students.

Mr. Pinter's class has twice as many students as Mrs. Rupert's class.

This means that:

[tex]x = 2y[/tex]

Mrs. Althouse's class has 20 less than three times Mrs. Rupert's class.

This means that:

[tex]z = 3y - 20[/tex]

Together they have 106 students.

This means that:

[tex]x + y + z = 106[/tex]

We have x and z has a function of y, so:

[tex]2y + y + 3y - 20 = 106[/tex]

[tex]6y = 126[/tex]

[tex]y = \frac{126}{6}[/tex]

[tex]y = 21[/tex]

And:

[tex]x = 2y = 2(21) = 42[/tex]

[tex]z = 3y - 20 = 3(21) - 20 = 63 - 20 = 43[/tex]

Mr. Pinter's class has 42 students, Mrs. Rupert's class has 21 students, and Mrs. Althouse's class has 43 students.

Answer:

l = 1920 cm

Step-by-step explanation:

Given that,

The radius of circle, r = 8 cm

The central angle is 240 degrees

We need to find the length of the arc. We know that,

[tex]l=r\theta[/tex]

Where

l is the length of the arc

So,

[tex]l=8\times 240[/tex]

[tex]\implies l=1920\ cm[/tex]

so, the length of the arc is equal to 1920 cm.

Answer:

Step-by-step explanation:

Polynomial f(x) has the following conditions: zeros of -2 (multiplicity 3), 3 (multiplicity 1), and with f(0) = 120.

The first part zeros of -2 means (x+2) and multiplicity 3 means (x+2)^3.

The second part zeros of 3 means (x-3) and multiplicity 1 means (x-3).

The third part f(0) = 120 means substituting x=0 into (x+2)^3*(x-3)*k =120

(0+2)^3*(0-3)*k = 120

-24k = 120

k = -5

Combining all three conditions, f(x)

= -5(x+2)^3*(x-3)

= -5(x^3 + 3*2*x^2 + 3*2*2*x + 2^3)(x-3)

= -5(x^4 + 6x^3 + 12x^2 + 8x - 3x^3 - 18x^2 - 36x - 24)

= -5(x^4 + 3x^3 - 6x^2 - 28x -24)

= -5x^4 - 15x^3 + 30x^2 + 140x + 120

Answer:

[tex]\frac{851}{1000}[/tex]

Step-by-step explanation:

First, we can simply multiply that number by 1000, and divide again by 1000 to get a base fraction:

[tex].851\\\\= \frac{1000}{1000} \times .851\\\\= \frac{1000 \times .851}{1000}\\\\= \frac{851}{1000}[/tex]

851 is a secondary prime, having only two factors, both of which are prime.  Those factors are 23 and 37, neither of which is a factor of 1000, so this is already in simplest form.

9514 1404 393

Answer:

  300

Step-by-step explanation:

Since nobody failed, the number who passed one or the other was 100%.

  P(O + W) = P(O) +P(W) -P(O&W)

  100% = 80% +70% -P(O&W)

  P(O&W) = 50% = 150 students

If 150 students are 50% of the examinees, then 100% will be 300 students.

Answer:

hope it helps

Answer:

1. log3 81 = 4

2. 4 3/2=8

Step-by-step explanation:

1. Convert the exponential equation to a logarithmic equation using the logarithm base (3)(3) of the right side (81)(81) equals the exponent (4)(4).

log3(81)=4

or

you can remember this

loga Y= X

so, a^x =y

2. Use the definition of a logarithm,

log

b

(

x

)

=

y

⟹

b

y

=

x

, to convert from the logarithmic form to the exponential form.

Answer:

16 √(3)

and then the decimal form if needed is: 27.7128129211

Step-by-step explanation:

Answer:

0.0069

Step-by-step explanation:

According to the Question,

We have, μ=22 , σ= 5 , P(X<9.7)=Area to the left of 9.7.

Z = (x-μ)/σ

Z = (9.7-22) / 5 ⇒ -2.46

Thus,

Answer:

3,199 approximately

Step-by-step explanation:

to find how much 20% of 15,998 does we multiply 15,998 with 20 and then divide it by 100

15,998 x 20 / 100 = 3,199

Answer:

y = 14

Step-by-step explanation:

[tex] \frac{15}{21} = \frac{5}{7} [/tex]

[tex] \frac{10}{x} = \frac{5}{7} [/tex]

[tex]x = 14[/tex]

Now,

10/15 = y/21

15y = 10*21

y = 210/15

y = 14

This is a Right answer...

I hope you understand..

Mark me as brainliest...

Answer:

You could save $20

Step-by-step explanation:

For buying them separately for $30 each for 5 people it would be $150 but if you buy the first option you would get 5 admission tickets for only $130

Answer:

20 dollars

Step-by-step explanation:

for the first deal is 5 for $130

and the second is for $30

$30 times 5 (the number of people) = $150

$150-$130= is 20

answer: $20

Flip the -1/4, cross deduct and should get 3/2

Answer:

It might be 3/2 or 1 and 1/2.

it right answer is Clovis 2.5% it answer

Answer:

0.924

Step-by-step explanation:

R² = 0.854

R = √0.854

R = 0.924

Hence, the correlation Coefficient of electricity tarrif is 0.924 ; this correlation Coefficient value, depicts a strong positive correlation between machine hours and cost of electricity. And can he interpreted to mean that ; Electricity tarrif increases as machine hours increases and also decreases as machine hours decreases.

Answer:

5

Step-by-step explanation:

Answer:

[tex]241^{257}\ mod\ 12 =1[/tex]

[tex]7 * 20 = 140[/tex]

[tex]\frac{1}{700}[/tex]

Step-by-step explanation:

Solving (a): 241^257 mod 12

To do this, we simply calculate [tex]241\ mod\ 12[/tex]

Because [tex]a\ mod\ b = a^n\ mod\ b[/tex]

The highest number less than or equal to 241 that is divisible by 12 is 240; So:

[tex]241\ mod\ 12 = 241- 240[/tex]

[tex]241\ mod\ 12 =1[/tex]

Hence:

[tex]241^{257}\ mod\ 12 =1[/tex]

Solving (b): 7 * 20

[tex]7 * 20 = 140[/tex]

Solving (c): Multiplicative inverse of 7 in 719

The position of 7 in 719 is 700

So, the required inverse is 1/700 ---- i.e. we simply divide 1 by the number

Answer:

Step-by-step explanation:

two points are (-5,-2) and (-1,3)

slope=(3-(-2))/(-1-(-5))=(3+2)/(-1+5)=5/4

Answer:

H0 : μN ≤ μD

H1 : μN > μD

Right tailed

Test statistic = 1.33

Pvalue = 0.097

Fail to reject the Null

Step-by-step explanation:

H0 : μN ≤ μD

H1 : μN > μD

The test is right tailed ; culled from the direction of the greater than sign ">"

Night students :

n1 =30 x1= 3.34 s1 = 0.02

Day students:

n2 = 30 x2 = 3.32 s2 = 0.08

The test statistic :

(x1 - x2) / √(s1²/n1) + (s2²/n2)

T= (3.34 - 3.32) / √(0.02²/30) + (0.08²/30)

T = 0.02 / 0.0150554

Test statistic = 1.328

Using the conservative approach ;

df = Smaller of n1 - 1 or n2 - 1

df = 30 - 1 = 29

Pvalue(1.328, 29) = 0.097

At α = 0.10

Pvalue < α ; Hence, we reject H0 ; and conclude that there is significant evidence that GPA of night student is greater than GPA of day student

Answer:

[tex]\text{Perimeter: }48\:\mathrm{m},\\\text{Area: }84\:\mathrm{m^2}[/tex]

Step-by-step explanation:

The area of a triangle with side lengths [tex]a[/tex], [tex]b[/tex], and [tex]c[/tex] is given by:

[tex]A=\sqrt{s(s-a)(s-b)(s-c)}[/tex], where [tex]s=\frac{a+b+c}{2}[/tex]

Substituting [tex]a=21, b=17, c=10[/tex], we have:

[tex]A=\sqrt{24(24-21)(24-17)(24-10)},\\A=\sqrt{24(3)(7)(14)},\\A=\sqrt{7,084},\\A=\boxed{84\:\mathrm{m^2}}[/tex]

The perimeter of a polygon is given by the sum of its sides. Since the triangle has sides 10, 17, and 21, its perimeter is [tex]10+17+21=\boxed{48\:\mathrm{m}}[/tex].

Answer:

0.9884 = 98.84% probability that the proportion of flops in a sample of 469 released films would be greater than 6%.

Step-by-step explanation:

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

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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 p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

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

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

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

A film distribution manager calculates that 9% of the films released are flops.

This means that [tex]p = 0.09[/tex]

Sample of 469

This means that [tex]n = 469[/tex]

Mean and standard deviation:

[tex]\mu = p = 0.09[/tex]

[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.09*0.91}{469}} = 0.0132[/tex]

What is the probability that the proportion of flops in a sample of 469 released films would be greater than 6%?

1 subtracted by the p-value of Z when X = 0.06. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.06 - 0.09}{0.0132}[/tex]

[tex]Z = -2.27[/tex]

[tex]Z = -2.27[/tex] has a p-value of 0.0116

1 - 0.0116 = 0.9884

0.9884 = 98.84% probability that the proportion of flops in a sample of 469 released films would be greater than 6%.

Answer:

tow degree of freedom.

this inform I know that from vibration method

Answer:

The answer is "18.087 years".

Step-by-step explanation:

For upper class:

[tex]\mu=15.45 \ years\\\\\alpha=2.98 \ years\\\\[/tex]

[tex]P(Z \leq 1.2)[/tex] from the standard normal distribution on the table:

[tex]P(Z \leq 1.2) =0.8849\\\\x=z_{\alpha}+\mu\\\\[/tex]

  [tex]=0.8849 \times 2.98 +15.45\\\\ = 2.637002+15.45 \\\\=18.087 \ \ years\\[/tex]

Answer:

$23.3

Step-by-step explanation:

you can use ratios to solve this:

$6.99/x=0.30/0.100 then cross multiply to get 0.3x=6.99

So, 6.99 divided by 0.3 = 23.3

so the original price is $23.3

Answer:

That transformation that happened was B rotation since b is rotated 180 degrees from A

Hope This Helps!!!

Answer:

1 : 0.088

2 : 0.12

3 : 0.07

Step-by-step explanation:

45 Rebullicans

50 Democrats

5 independents

Total = 100

Selection =  3

Part 1:

(45 C 3) / (100 C 3) = 0.088

Part 2:

(50 C 3) / (100 C 3) = 0.12

Part 3:

(45 C 1) x (50 C 1) x (5 C 1) / (100  C 3) = 0.07

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Answer:

Step-by-step explanation:

There are a couple of relations that are applicable to these questions.

__

The segment lengths relation tells us ...

  10x = 8×7 . . . . . . products of segment lengths are equal

  x = 56/10 = 5.6 . . . . divide by 10

__

The value of y° is the average of the intercepted arcs:

  y° = (85° +45°)/2 = 65°

_____

Additional comment

This diagram does not have enough information to allow computation of z. We would need to know the intercepted arc, or the length of the secant that meets tangent z.

Answer:

Note: See the attached photo for the graph showing Weight Not Over (lbs.) vs Price($). The attached excel file also shows the same graph with the data used to draw it in the excel.

Step-by-step explanation:

In the attached graph, Weight Not Over (lbs.) is on the horizontal axis while Price ($) is on the vertical axis.

From the attached, it can be observed that the graph shows an upward trend. That implies that there is a positive relation between Weight Not Over (lbs.) and Price. That is, as Weight Not Over (lbs.) rises, the Price also rises.

Answer:

Step-by-step explanation:

Partindo do pressuposto de que você pode ter coberturas duplas e triplas do mesmo item, o cálculo é relativamente simples. Para calcular as combinações possíveis; deve-se multiplicar as coberturas disponíveis pelo número total de coberturas permitidas. Este cálculo é semelhante a como olhamos para diferentes sistemas de contagem de base. Normalmente contamos com decimais (base 10), portanto, o número de combinações, se usar 3 dígitos, seria calculado por 10 x 10 x 10.

10x10 = 100

100x10 = 1000 combinações (0 a 999)

Sua pergunta sobre coberturas de pizza é a mesma, mas assumindo um sistema de numeração de base 12, então 12x12x12 ou 12³

Portanto, 1.728 combinações incluindo 0 (sem coberturas?) E também incluindo 12 ocasiões em que todas as 3 coberturas seriam iguais. Se esses cenários de pessoas forem restritos de modo que você só possa ter coberturas duplas máximas, etc., então essas combinações devem ser removidas (subtraídas do total de combinações permitidas).

Espero ter ajudado você a entender os princípios, então você deve ser capaz de trabalhar a partir disso, de muitas outras soluções semelhantes