In: Math
For 300 trading days, the daily closing price of a stock (in $) is well modeled by a Normal model with mean $197.49197.49 and standard deviation $7.147.14. According to this model, what is the probability that on a randomly selected day in this period the stock price closed as follows.
a) above $211.77211.77?
b) below $204.63204.63?
c) between $183.21183.21 and $211.77211.77?
d) Which would be more unusual, a day on which the stock price closed above $210210 or below $190190?
We are talking in the period of 300 days.
Let X represent the closing price of the stock. Then we have:
a)
We need to compute
The corresponding z-value needed to be computed is:
Therefore, we get that
b)
We need to compute
The corresponding z-value needed to be computed:
Therefore,
c)
d) The stock price ending above 210 is more unusual.
Case I
We need to compute . The corresponding z-value needed to be computed is:
Therefore, we get that
Case II
We need to compute
The corresponding z-value needed to be computed:
Therefore,
Please upvote. Let me know in the comments if anything is unclear. I will reply ASAP!