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 less than or equal to 64 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(Less than or equal to 64 inches)
P(X ≤ 64)
When x = 64
z = `(64 - 68)/3 = (-4)/3 = - 1.33`
P(X ≤ 64) = P(Z ≤ – 1.33)
P(Z ≥ – 1.33)
= 0.5 – 0.4082
= 0.0918
∴ Number of heights who ate less than or equal to 64 inches
= 0.0918 × 500
= 45.9
= 46 .......(approximately)
APPEARS IN
संबंधित प्रश्न
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 find the mean and variance
If 18% of the bolts produced by a machine are defective, determine the probability that out of the 4 bolts chosen at random none will be defective
Out of 750 families with 4 children each, how many families would be expected to have atleast one boy
The mean of a binomial distribution is 5 and standard deviation is 2. Determine the distribution
Write down the conditions in which the Normal distribution is a limiting case of binomial distribution
Time taken by a construction company to construct a flyover is a normal variate with mean 400 labour days and a standard deviation of 100 labour days. If the company promises to construct the flyover in 450 days or less and agree to pay a penalty of ₹ 10,000 for each labour day spent in excess of 450. What is the probability that the company takes at most 500 days to complete the flyover?
Choose the correct alternative:
Forty percent of the passengers who fly on a certain route do not check in any luggage. The planes on this route seat 15 passengers. For a full flight, what is the mean of the number of passengers who do not check in any luggage?
Choose the correct alternative:
The time until the first failure of a brand of inkjet printers is normally distributed with a mean of 1,500 hours and a standard deviation of 200 hours. What proportion of printers fails before 1000 hours?
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?
The annual salaries of employees in a large company are approximately normally distributed with a mean of $50,000 and a standard deviation of $20,000. What percent of people earn more than $75,000
