1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Oduvanchick [21]
3 years ago
9

Randomly meeting someone whose social security number ends in the same digit as yours

Mathematics
2 answers:
7nadin3 [17]3 years ago
8 0
The last four are usually identifiers, like year born state and race. Believe it or not it's more common than you think.

This can be translated into the question: What is the probability of having the same last 4 digits as someone else in a Social Security Number (SSN). This is far higher than one would expect.

<span>Out of 119 people, there is a 50% chance that two of them will have the same last 4 digits in their SSN.Out of 180 people, there is a 80% chance that two of them will have the same last 4 digits in their SSN.Out of 300 people, then there is more than 99% probability that two of them will have the same number.</span>

The Theory:

When considering what the probability is that two people have the same last four digits, one takes into account how many people you are comparing. If there are 4 people in the room, the chance of two people having the same last 4 digits can be calculated as follows:

It is important to take into account the comparisons between all individuals. The chance of two numbers not matching is 9999/10000. However if there are 4 people in the room:

<span>Chance A doesn’t match to B = 9999/10000Chance A doesn’t match to C given that A didn’t to B = 9998/10000Chance A doesn't match to D, given that A did not match to B or C if 9997/10000.</span>

Hence the total chance of A not matching any of B, C or D is

The chance that A does match either B, C or D is

As you increase the number of people from 4 upwards, the probability increases exponentially. The probability of two people having the same last 4 digits out of more than 10000 people is 0.9999.

Record Linkage:

So how does this affect the score assigned to the 4 digit SSN in record linkage? The best is to think of score relative to additional attributes.

<span><span>9 digit SSN – Out of 10000 people, the chance of any two sharing a SSN is 0.04. This is purely mathematical and ignores the fact that SSN is issued without replacement – i.e. uniquely. Out of 10000 people, there is almost certainty that 2 people will share the same 4 digit SSN.

Hence, the score given to a 4 digit SSN should be significantly lower than that given to a 9 digit SSN. I would recommend that it is least 20x less than the 9 digit SSN.

</span><span><span>Date of Birth – If we consider all dates of birth over a range of 100yrs then there are 36,525 possible birth dates. If we consider 10,000 people then the chance of any two of them having the same Date of Birth is > 0.99. It is very similar to that of 4 digit SSN.

</span><span>Hence in terms of scores, it is advisable to score the 4 digit SSN the same if not slightly less than Date of Birth. If your population consists only economically viable adults then the same score should be applied to both Date of Birth and the 4 digit SSN.
</span></span></span>
via http://www.visionware.com/us/blog/posts/2015/november/how-unique-are-the-last-4-digits-of-a-social-s...
Galina-37 [17]3 years ago
3 0
That is very cool and rare if you did it nice job!
You might be interested in
Sterre charges $35 to file tax returns, but files for free if she only needs the easiest form. Then she donates $2 to clean wate
borishaifa [10]

We have been given that Sterre charges $35 to file tax returns, but files for free if she only needs the easiest form. Also, she donates $2 to clean water projects per tax return she files.

Further we know that Sterre charged $7,245 and made a donation of $1,242 this year for the tax returns she filed.

Let x be the number of free income tax returns and y be the number of $35 income tax returns.

Therefore, we can set up:

0\times x+35\times y=7245\Rightarrow 35y=7245\Rightarrow y=\frac{7245}{35}=207

Since she donates $2 for each return that she files, therefore, we can set up:

2(x+y)=1242\Rightarrow x+y=621\Rightarrow x+207=621\Rightarrow x=414

Therefore,

Sterre filed 414 tax returns for free and filed 207 tax returns for $35.

7 0
3 years ago
1. What number is 27% of 52?
Goshia [24]
14 or 14.04 if you want to be more specific
8 0
3 years ago
Read 2 more answers
Which dot plot has the largest range?
romanna [79]

Answer:

Calico Crayfish has the largest range ⇒ The range = 9

Step-by-step explanation:

∵ The rang is the difference between the largest value

   and the smallest value

In the Calico Crayfish the largest value is 10 and the smallest value is 1

∴ The range = 10 - 1 = 9

In the Zebra Mussel the largest value is 10 and the smallest value is 2

∴ The range = 10 - 2 = 8

In the Blue-back Herring the largest value is 10 and the smallest value is 4

∴ The range = 10 - 4 = 6

In the Shield Darter the largest value is 9 and the smallest value is 2

∴ The range = 9 - 2 = 7

∴ The largest range is 9 in Calico Crayfish

8 0
3 years ago
Read 2 more answers
Tia has a goldfish pond in her backyard. She has a white goldfish that is 11 inches long. This is 3 inches
alexandr1967 [171]

Answer:

The orange goldfish is 25 inches long

Step-by-step explanation:

Sorry I hope my answer makes sense, his question was a lil hard to read

2 x 11 = 22 + 3= 25

5 0
2 years ago
Read 2 more answers
3 questions.. answer all pls
den301095 [7]

Answers:

1. 1/4

2. 12:10

3. 3/23 in fraction form, or 0.13 in decimal form (though please note that the decimal form has been rounded to the nearest hundredth).

Explanations:

1. In order to simplify a fraction, you need to find a number that both the numerator and denominator can be divided by evenly. Once you cannot find any number that fits that description, you have found the simplest form. Both numbers 10 and 40 can be divided by the number 10 - so let's divide 10 by 10 and 40 by 10. After doing that, your answer should be 1/4.

2. In order to find an equivalent ratio of an existing ratio, you can just multiply or divide the numbers of that ratio by a same number. Knowing this, this question can have many correct answers, but in this case, I used the number 2, and multiplied both 6 and 5 by it. This left me with an equivalent ratio of 12:10.

3. In order to calculate probability, you need to divide the number of "winners" (or the outcome we want to have) by the number of all possible outcomes you could have. For this problem, that "winner" is the number of green shirts, which is 3. The number of outcomes would be the number of all the shirts in total, which adds up to 23. Thus, using that method explained earlier, the probability would be 3/23 in fraction form or 0.13 in decimal form (note that this is rounded to the nearest hundredth since dividing 3 by 23 would result in a long answer).

8 0
2 years ago
Other questions:
  • Describe steps to simplify w(5w^3)^-2 / w^-4
    12·1 answer
  • What are the laws of exponents
    8·2 answers
  • Factor the expression 49b²-36​
    6·1 answer
  • Tengo 5 manzanas y me regalan dos ​
    8·1 answer
  • Find the slope of the line passing through each of the following pairs of points. b (−3, 9), (−3, −5)
    8·2 answers
  • Which expression has a value of 60?
    6·1 answer
  • I asked this but no1 knows it.So if any1 whos older or smart 4 an 8th grader please help me.Im just tryna pass​
    15·1 answer
  • 21 cm by 18cm by 15 cm what will the total sq cm
    6·1 answer
  • Can someone help on both of the questions, i dont get it
    6·1 answer
  • Robert is preheating his oven before using it to bake. The initial temperature of the oven is 65° and the temperature will incre
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!