Standard Normal Distribution Table The entries in the table give the areas under

Question

Standard Normal Distribution Table The entries in the table give the areas under the standard nn Page 2 of 8 CASIO The strength of certain type of a thread is a random variable with a mean o f 0.93 is the sum of the threads in the rope. Find th consisting of 100 threads is at least 95 kilograms ation of 0.25 kilogram. Assume that the strength of a rope e probability that the strength of a rope a) 0.7881 b) 02119 c)0.2881 d) None of these Suppose that 65 % of NDU students have their own cars. If 70 NDU students were randomly selected, approximate the probability that more than 50 of them have their own cars a) 00838 b) 0.8944 d) None of these c)0.1056 Ifi is the mean of a random sample of size n selected from a population with mean then the" CENTRAL LIMIT THEOREM states that

Explanation / Answer

Since there are n=100 threads

mean of rope, u = 100*mean of thread = 100*0.93 = 93kg

standard deviation, sigma = sqrt(100) * standard deviation of thread = 2.5

We need to find P(X>95)

Z = (X-u)/sigma = (95 - 93)/2.5 = 0.8

P(X>95) = 1 - P(X<95)

= 1 - normal distritbution (Z<0.8)

= 1 - 0.7881 (Using normal distribution table)

= 0.2119

So option B is the correct answer.

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.