Neurons and their synapses can be studied in the intact brain of a mouse using t

Question

Neurons and their synapses can be studied in the intact brain of a mouse using two-photon excitation laser scanning microscopy through a chronic cranial window. Installing the chronic cranial window technique is difficult. Suppose that a technician with 2 years of experience can install 30 out of 50 mice successfully. What is the minimum number of mice that you need such that you would have a 85% probability that you will have at least 5 mice with successfully installed chronic cranial window for your imaging study? Solve using the two different ways as shown in the class (Use the table.) Plot the probability distribution and the cumulative probability distribution that corresponds to Method 1 and Method 2 in (a). (Use MATLAB)

Explanation / Answer

Solution

Let X = Number of mice successfully installed. Then, X B(n, p), where n = number of mice tried and p = probability of successfully installing a mouse.

In the given question, we need to find n such that

P(at least 5 mice are successfully installed) = 0.85 or

P(X 5) = 0.85 where X B(n, 0.6); [30 out of 50 are given to be successful]   

P(X 5) = 0.85 is also equivalent to P(X < 5) = 0.15 or P(X 4) = 0.15 [this conversion makes it easy to find n from Binomial Cumulative Probability Table or by using Excel function]

Using Excel function, P(X 4) = 0.1662 for n = 10 and P(X 4) = 0.0994 for n = 11.

So, 11 mice must be tried ANSWER

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

---