All categories

3 years ago

Prove that the recurring decimal 0.39 = 13/33

1 answer:

8 0

$x=0.\overline{39}\\100x=39.\overline{39}\\
100x-x=39.\overline{39}-0.\overline{39}\\
99x=39\\
x=\dfrac{39}{99}=\dfrac{13}{33}
$

You might be interested in

What should I buy? A study conducted by a research group in a recent year reported that of cell phone owners used their phones i

Llana [10]

Answer:

The probability that seven or more of them used their phones for guidance on purchasing decisions is 0.7886.

Step-by-step explanation:

The question is incomplete:

What should I buy? A study conducted by a research group in a recent year reported that 57% of cell phone owners used their phones inside a store for guidance on purchasing decisions. A sample of 14 cell phone owners is studied. Round the answers to at least four decimal places. What is the probability that seven or more of them used their phones for guidance on purchasing decisions?

We can model this as a binomial random variable, with p=0.57 and n=14.

$P(x=k)=\dbinom{n}{k} p^{k}q^{n-k}$

a) We have to calculate the probability that seven or more of them used their phones for guidance on purchasing decisions:

$P(x\geq7)=\sum_{k=7}^{14}P(x=k)\\\\\\$

$P(x=7)=\dbinom{14}{7} p^{7}q^{7}=3432*0.0195*0.0027=0.1824\\\\\\P(x=8) = \dbinom{14}{8} p^{8}q^{6}=3003*0.0111*0.0063=0.2115\\\\\\P(x=9) = \dbinom{14}{9} p^{9}q^{5}=2002*0.0064*0.0147=0.1869\\\\\\P(x=10) = \dbinom{14}{10} p^{10}q^{4}=1001*0.0036*0.0342=0.1239\\\\\\P(x=11) = \dbinom{14}{11} p^{11}q^{3}=364*0.0021*0.0795=0.0597\\\\\\P(x=12) = \dbinom{14}{12} p^{12}q^{2}=91*0.0012*0.1849=0.0198\\\\\\P(x=13) = \dbinom{14}{13} p^{13}q^{1}=14*0.0007*0.43=0.004\\\\\\$

$P(x=14) = \dbinom{14}{14} p^{14}q^{0}=1*0.0004*1=0.0004\\\\\\$

$P(x\geq7)=0.1824+0.2115+0.1869+0.1239+0.0597+0.0198+0.004+0.0004\\\\P(x\geq7)=0.7886$

7 0

3 years ago

Look at the photo and put your answer down.

Margarita [4]

No solution, I hope I helped (:

8 0

3 years ago

Read 2 more answers

A number,Y,is 2 less than half of a number X

zhenek [66]

Answer: y = 0.5x - 2

Step-by-step explanation: 0.5x = half of a number X

8 0

3 years ago

QUICK I NEED ANSWERS NOW.. I NEED CORRCT ANSWER.. I WILL MARK BRAINLIEST.

valina [46]

Well for both of these I would say for question 1:

1. Having low paid jobs and are unable to get a home and are poor

2. Having difficulties with switching cultures

3. They wanted an anarchist

And for the muckrakers:

1. They made the child labor laws rewritten

2. They made fair business practices

3. They exposed political corruption

Also if these are similar to some other answer I just wanted to help.

3 0

3 years ago

Read 2 more answers

Write the estimated weight of each dinosaur in scientific notation.

Lubov Fominskaja [6]

Argentinosaurus- 2.2x10^5

Brachiosaurus- 1.0x10^5

Apatosaurus- 6.6x10^4

Diplodocus- 5.0x10^4

Camarasourus- 4.0x10^4

Cetioauriscus- 1.985X10^4

I hope this helps :3

6 0

4 years ago

Read 2 more answers