Answer:
The required probability is 0.031918.
Step-by-step explanation:
Consider the provided information.
It is given that According to an article in The Wall Street Journal, this theory held for 22 out of the last 34 years.
Therefore n=34
The probability it is either up or down is 0.5.
Thus the value of p =0.5 and q = 0.5
Now calculate the probability
Let X is the number of years that theory held.
X has a binomial distribution with n=34 and p=0.5
[tex]P(X=22)=\binom{34}{22}(0.5)^{22}(0.5)^{12}\\P(X=22)=\frac{34!}{22!\times 12!}(0.5)^{22}(0.5)^{12}\\P(X=22)=548354040\times 5.8207660913\times 10^{11}\\P(X=22)=0.0319184060208\\P(X=22)\approx0.031918[/tex]
Hence, the required probability is 0.031918.
