Statistics and Probability Answers

2) In a factory turning out razor blade, there is a small chance of 1/500 for many blade to be defective. The blades are supplied in a packet of 10. Use poisson distribution to calculate the approximate number of packets containing blades with no defective, two defective and three defectives blades in a consignment of 10,000 packets?

Calculate the standard deviation from following data?
Size of items
6
7
8
9
10
11
12
Frequency
3
6
9
13
8
5
4

An urn A contains 2 white & 4 black balls. Another urn B contains 5 white & 7 black balls. A ball is transferred from urn A to urn B, then a ball is drawn from urn B. Find the probability that it is white

Suppose you toss a coin 4 times what is the probability that you get four tails? Write the probability as a fraction.

A sample of 400 students of undergraduate and 400 students of post graduate classes were taken to know their opinion about autonomous college. 290 of the undergraduate and 310 of the post graduate students favoured the autonomous status. Present these fact in the form of a table and the test at 5% level, that the opinion regarding autonomous status of colleges are independent of the level of classes of students.

4. Test the significance of variation of the retail prices of the commodity in three principle cities; Bombay, Kolkata and Delhi. The four shops were chosen at random in each city and prices observed in rupees were as follows
Bombay 16 8 12 14
Kolkata 14 10 10 6
Delhi 4 10 8 8

2. In a factory turning out razor blade, there is a small chance of 1/500 for any blade to be defective. The blades are supplied in a packet of 10. Use Poisson distribution to calculate the approximate number of packets containing blades with no defective, one defective, two defectives and three defectives in a consignment of 10,000 packets.

A chartered accountant applies for a job in two firms X and Y. He estimates that the probability of his being selected in firm X is 0.7 and being rejected in Y is 0.5 and the probabilty that atleast one of his applications rejected is 0.6. What is the probability that he will be selected in one of the firms?

Car security alarms go off at a mean rate of 4.0 per hour in a large Costco parking lot.

Find the probability that in an hour there will be (Round your answers to 4 decimal places.)

Probability
(a) no alarms
(b) fewer than five alarms
(c) more than seven alarms

The lifetime X of a bulb is a random variable with the probability density function:

f(x)={ 6[0.25-(X-1.5)^2] when 1<=X<=2
f(x)={ 0 Otherwise
X is measured in multiples of 1000 hrs. What is the probability that none of the three
bulbs in a traffic signal have to be replaced in the first 1500 hrs of their operation.