The score in a certain examination follows normal distribution with mean 50 and standard deviation 16 then the marks of top 1% candidates will have score more than .................. .
87
For a normal distribution, a cut-off score x is found from the standard normal variate z: x = mean + z × standard deviation = 50 + 16z.
The top 1% of candidates lie in the upper tail with area 0.01; from the standard normal table, the z-value leaving 1% area to its right is about 2.33.
So x = 50 + 16 × 2.33 = 50 + 37.28 = 87.28, i.e. about 87 marks.
Hence, the answer is 87.
If A and B are independent events with P(A) = 0.7 and P(B) = 0.8, then P(A∪B) = .................... .
Suppose the number of accidents per week on a certain highway follows Poisson distribution with mean 2 then the percentage of weeks having no accidents is ....................
(Given e-2 = 0.1353)
A box contains 8 white and 3 red balls. If two balls are drawn at random, find the probability that one is white and one is red.
For a normal curve with mean of 120 and standard deviation of 35, what proportion (in percent) of the area under the curve will lie between the values of 85 and 155 ?
A book contains 600 typographic errors in its 600 pages. These typo errors occur completely at random. Using the Poisson distribution, the probability, that a page contains no error, is :