Answer:
57%
Step-by-step explanation:
Given
Number of kids = 25
Probability that 20 or fewer kids like Pizza = 43%
Required
Probability that at least 21 kids in the same group like pizza
In probability, summation of opposite probabilities is always equal to 1;
The opposite of 20 or fewer kids is 21 or more kids
<em>21 or more kids means at least 21 kids</em>
Since we mentioned that summation of opposite probability is always equal to 1
This can be represented as follows;
Probability of 20 or fewer kids + Probability of 21 or more kids = 1
Given that Probability that 20 or fewer kids like Pizza is 43%;
<em>By substitution, we have</em>
43% + Probability of 21 or more kids = 1
<em>Collect like terms</em>
Probability of 21 or more kids = 1 - 43%
<em>Convert percentage to decimal</em>
Probability of 21 or more kids = 1 - 0.43
Probability of 21 or more kids = 0.57
<em>Convert decimal to percentage</em>
Probability of 21 or more kids = 57%
Hence, the probability that at least 21 kids in the group like Pizza is 57%
