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
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
A pair of dice is thrown 4 times. If getting a doublet is considered a success, find the probability of 2 successes
Write any 2 examples for Poisson distribution
A car hiring firm has two cars. The demand for cars on each day is distributed as a Poison variate, with mean 1.5. Calculate the proportion of days on which some demand is refused
The average number of phone calls per minute into the switchboard of a company between 10.00 am and 2.30 pm is 2.5. Find the probability that during one particular minute there will be exactly 3 calls
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 more 1,920 hours but less than 2,100 hours
Choose the correct alternative:
If for a binomial distribution b(n, p) mean = 4 and variance = 4/3, the probability, P(X ≥ 5) is equal to
Choose the correct alternative:
The starting annual salaries of newly qualified chartered accountants (CA’s) in South Africa follow a normal distribution with a mean of ₹ 180,000 and a standard deviation of ₹ 10,000. What is the probability that a randomly selected newly qualified CA will earn between ₹ 165,000 and ₹ 175,000?
Choose the correct alternative:
Monthly expenditure on their credit cards, by credit cardholders from a certain bank, follows a normal distribution with a mean of ₹ 1,295.00 and a standard deviation of ₹ 750.00. What proportion of credit cardholders spend more than ₹ 1,500.00 on their credit cards per month?
Choose the correct alternative:
In a binomial distribution, the probability of success is twice as that of failure. Then out of 4 trials, the probability of no success is
The time taken to assemble a car in a certain plant is a random variable having a normal distribution of 20 hours and a standard deviation of 2 hours. What is the probability that a car can be assembled at this plant in a period of time. Between 20 and 22 hours?
