Mean : m = 2.2
Standard deviation: s = 0.3
m - 1 s = 2.2 - 0.3 = 1.9
m + 1 s = 2.2 + 0.3 = 2.5
For the normal distribution the values less than 1 standard deviation away from the mean account for 68.27 % of the set.
Answer: D ) 68 %
Based on the information given, it should be noted that the least number of marbles that can be in the bag will be 10 marbles.
<h2>
Solution to the probability.</h2>
If the bag contains 60 marbles, the number of red marbles will be:
= 1/5 × 60
= 12 marbles.
The number of white marbles will be:
= 3/10 × 60
= 18 marbles.
The number of blue marbles will be:
= 60 - (12 + 18)
= 60 - 30
= 30 marbles.
Furthermore, when the bag has 4 red marbles and 6 white marbles, there'll be 10 blue marbles.
Lastly, to find the probability of choosing a blue marble, we've to multiply 1/2 by the number given.
Learn more about probability on:
brainly.com/question/25870256
