Advertisements
Advertisements
प्रश्न
If the heights of 500 students are normally distributed with mean 68.0 inches and standard deviation 3.0 inches, how many students have height greater than 72 inches
Advertisements
उत्तर
Let x denote the height of a student N = 500; m = 68.0 inches and σ = 3.0 inches the standard normal variate
z = `(x - mu)/sigma = (x - 68)/3`
P(Greater than 72 inches)
P = P(X > 72)
When x = 72
z = `(72 - 68)/3 = 4/3` = 1.33
P(x > 72) = P(z > 1.33)
= 0.5 – 0.4082
= 0.0918
Number of students whose height are greater than 72 inches
= 0.0918 × 500
= 45.9
= 46 ......(approximately)
APPEARS IN
संबंधित प्रश्न
Derive the mean and variance of binomial distribution
If 5% of the items produced turn out to be defective, then find out the probability that out of 20 items selected at random there are exactly three defectives
In a particular university 40% of the students are having newspaper reading habit. Nine university students are selected to find their views on reading habit. Find the probability that atleast two-third have newspaper reading habit
Among 28 professors of a certain department, 18 drive foreign cars and 10 drive local made cars. If 5 of these professors are selected at random, what is the probability that atleast 3 of them drive foreign cars?
Write down any five chief characteristics of Normal probability curve
In a test on 2,000 electric bulbs, it was found that bulbs of a particular make, was normally distributed with an average life of 2,040 hours and standard deviation of 60 hours. Estimate the number of bulbs likely to burn for less than 1,950 hours
In a distribution 30% of the items are under 50 and 10% are over 86. Find the mean and standard deviation of the distribution
Choose the correct alternative:
In a parametric distribution the mean is equal to variance is
Choose the correct alternative:
A statistical analysis of long-distance telephone calls indicates that the length of these calls is normally distributed with a mean of 240 seconds and a standard deviation of 40 seconds. What proportion of calls lasts less than 180 seconds?
A manufacturer of metal pistons finds that on the average, 12% of his pistons are rejected because they are either oversize or undersize. What is the probability that a batch of 10 pistons will contain no more than 2 rejects?
