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Can't understand this. Can anyone tell me the answer -

Can't understand this. Can anyone tell me the answer --example-1
User Ckot
by
2.5k points

1 Answer

7 votes
7 votes

Hi,

The first thing you have to remember, that the sum of all probabilities are equal to 1.

As you have only 4 items : Pasta + Fish + Pizza +Salad

So pasta + fish + pizza +salad = 1

1 means every client who bought something had something to eat.

So now it simple :

We know the probability of every other items, so we will find the probabilty of salad by substracting off 1 every other probabilities.

Remind yourself to always have data in same shape/ units etc.

Here we have percentage, fraction, numbers.... can be confusing.

So convert all in same shape. I 'm going to convert all in numbers, as it seems to me the simpliest.

I will call probability of salad "X" as it usually like that we call something unknown in math.

So pasta = 15 % = 15/100 = 0.15

fish = 0.2

pizza = 3/10 = 0.3

salad = X

So now we have :

pasta + fish + pizza +salad = 1

replace by what I know :

0.15 +0.2+0.3 + X = 1

0.65 + X = 1

0.65 +X -0.65 = 1 - 0.65

X = 0.35

Salad probability is 0.35 , which means 35 % .

User ArjunShankar
by
3.0k points