Question

When we know population data, but have a sample to work with, we use the formula...

When we know population data, but have a sample to work with, we use the formula above to compute a Z score.

  1. If the cholesterol level of men in the community is normally distributed with a mean of 200 and a standard deviation of 25, what is the probability that a randomly selected sample of 49 men will have a mean between 190 and 205?

Homework Answers

Answer #1

Solution :

Given that,

mean = = 200

standard deviation = = 25

= / n = 25 / 49 = 3.5714

= P[(190 - 200) / 3.5714 < ( - ) / < (205 - 200) / 3.5714)]

= P(-2.8 < Z < 1.4)

= P(Z < 1.4) - P(Z < -2.8)

= 0.9192 - 0.0026

Probability = 0.9166

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
1. Several baseline studies are conducted on X = “cholesterol level (mg/dL)” in a certain population...
1. Several baseline studies are conducted on X = “cholesterol level (mg/dL)” in a certain population of individuals. From the given information described below for each of these studies, choose the LETTER of the most appropriate statistical test to be implemented, from the following list. Note: For each study, there is only one correct choice of test. However, a given statistical test can be the correct choice for more than one study. For example, choice A could be the correct...
Suppose that we will randomly select a sample of 79 measurements from a population having a...
Suppose that we will randomly select a sample of 79 measurements from a population having a mean equal to 21 and a standard deviation equal to 8. (a) Describe the shape of the sampling distribution of the sample mean . Do we need to make any assumptions about the shape of the population? Why or why not? Normally distributed ; yes , because the sample size is large . (b) Find the mean and the standard deviation of the sampling...
3. 1: Standard Normal Distribution Table of the Area between 0 and z A population is...
3. 1: Standard Normal Distribution Table of the Area between 0 and z A population is normally distributed with μ = 200 and σ = 20. a. Find the probability that a value randomly selected from this population will have a value greater than 225. b. Find the probability that a value randomly selected from this population will have a value less than 190. c. Find the probability that a value randomly selected from this population will have a value...
A variable of a population has a mean of ?=150 and a standard deviation of ?=21....
A variable of a population has a mean of ?=150 and a standard deviation of ?=21. a. The sampling distribution of the sample mean for samples of size 49 is approximately normally distributed with mean __ and standard deviation __ A company sells sunscreen in 500 milliliters (ml) tubes. In fact, the amount of lotion in a tube varies according to a normal distribution with mean ?=497 ml and a standard deviation ?=5 ml. Suppose a store that sells this...
Scores from the UCLA Loneliness Scale are normally distributed with a mean of 40 and a...
Scores from the UCLA Loneliness Scale are normally distributed with a mean of 40 and a standard deviation of 10. showing the work, What is the probability that a randomly selected individual from the population will have a score below 30? d. What is the probability that a randomly selected individual from the population will have a score above 60?
Suppose we know that examination scores have a population standard deviation of σ = 25. A...
Suppose we know that examination scores have a population standard deviation of σ = 25. A random sample of n = 400 students is taken and the average examination score in that sample is 75. Find a 95% and 99% confidence interval estimate of the population mean µ.
IQ scores in a certain population are normally distributed with a mean of 101 and a...
IQ scores in a certain population are normally distributed with a mean of 101 and a standard deviation of 13. (Give your answers correct to four decimal places.) (a) Find the probability that a randomly selected person will have an IQ score between 99 and 108. (b) Find the probability that a randomly selected person will have an IQ score above 89
In a population, u = 100 and sx = 25. A sample of 150 people has...
In a population, u = 100 and sx = 25. A sample of 150 people has a mean of 120. Using two tails and a criterion of .05, what is the critical value? Compute standard error of the mean (σX) and z-score of the sample mean. Show your work. Is the sample mean in the region of rejection and how do you know? (Hint: draw it out) Should we conclude that this sample is representative of the population? Why or...
1.) Suppose we have a normally distributed population of scores with mean 150 and standard deviation...
1.) Suppose we have a normally distributed population of scores with mean 150 and standard deviation 52. We know the standard error of the mean is 4. What is the value of the sample size? 2.) Suppose we have a normally distributed population of scores with mean 300 and standard deviation 45. We know the standard error is 3. What is the value of the sample size?
A population is normally distributed with μ=200 and σ=10. a. Find the probability that a value...
A population is normally distributed with μ=200 and σ=10. a. Find the probability that a value randomly selected from this population will have a value greater than 210. b. Find the probability that a value randomly selected from this population will have a value less than 190. c. Find the probability that a value randomly selected from this population will have a value between 190 and 210. a. ​P(x>210​)= ​(Round to four decimal places as​ needed.) b. ​P(x<190​)= ​(Round to...