The mean weight of 1000 students at a certain college is 62 kg, and the standard deviation is 5kg. Assuming that the weights are normally distributed, find the probability that a randomly selected student weighs between 55 and 60kg.a.0.3446b.0.0808c.0.2638d.0.7362
Question
The mean weight of 1000 students at a certain college is 62 kg, and the standard deviation is 5kg. Assuming that the weights are normally distributed, find the probability that a randomly selected student weighs between 55 and 60kg.a.0.3446b.0.0808c.0.2638d.0.7362
Solution
To solve this problem, we need to use the concept of Z-scores in statistics. The Z-score is a measure of how many standard deviations an element is from the mean.
Step 1: Calculate the Z-scores for 55kg and 60kg.
The formula for a Z-score is Z = (X - μ) / σ, where X is the value we're interested in, μ is the mean, and σ is the standard deviation.
For 55kg: Z1 = (55 - 62) / 5 = -1.4 For 60kg: Z2 = (60 - 62) / 5 = -0.4
Step 2: Look up these Z-scores in a standard normal distribution table, or use a calculator that can do this for you.
The values you get from the table are the probabilities that a value is less than your given value.
For Z1 = -1.4, the probability P(Z < -1.4) = 0.0808 For Z2 = -0.4, the probability P(Z < -0.4) = 0.3446
Step 3: Subtract the two probabilities to get the probability that a student weighs between 55kg and 60kg.
P(55kg < X < 60kg) = P(Z < -0.4) - P(Z < -1.4) = 0.3446 - 0.0808 = 0.2638
So, the probability that a randomly selected student weighs between 55 and 60kg is 0.2638 or 26.38%. Therefore, the correct answer is c. 0.2638.
Similar Questions
The mean weight of students at a certain college follows a normal distribution with a mean of 80kg and a standard deviation of 15kg. a. What is the probability that a randomly selected student weighs more than 50kg? (Give your answer to 4 decimal places.) Blank 1b. Find the value c such that P (|X - 80| < c) = 0.95. Blank 2
In a distribution exactly normal with mean 47.5 Kilogram, 89.97% of the items are under 70 kilogram weight. Then which of the following is the standard deviation of the distribution? Given that area under standard normal curve from Z=0 to Z=1.28 is 0.3997.
An investigator wants to assess whether the mean (mu) = the average weight of passengers flying on small planes exceeds the FAA guideline of average total weight of 185 pounds (passenger weight including shoes, clothes, and carry-on). Suppose that a random sample of 25 passengers showed an average total weight of 200 pounds with a sample standard deviation of 59.5 pounds. Assume that passenger total weights are normally distributed.What is the value of the test statistic? Group of answer choicest = 1,8t = 1.50t = 1.65t = 1.26
Weights of women in one age group are normally distributed with a standard deviation of 10.43 kg. A researcher wishes to estimate the mean weight of all women in this age group.Find how large a sample must be drawn in order to be 95% confident (use z=2) that the sample mean will not differ from the population mean by more than 1.30 kg.
A population of adult free-range turkeys has a mean weight of 8.5 kg and a standard deviation of 1.2 kg. A random sample of size 10 is taken from this population. Find the mean and the standard deviation for the total weight of this sample of size 10.
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.