The mean of the sample was found to be 38,000 miles meaning that this brand of tire, when sampled, lasted on average approximately 38,000 miles. A sample of 31 tires has been tested for mileage. Assume the list of 7th graders' weights is the population and choose a sample of size 5 using the random number table you have already received. To try to develop a sampling distribution from which such an approximation of μ for the population of all 7th grade boys' weights can be made. In other words, we want to use the sample mean, x-bar ( X ), to make an inference about the value of the parameter, μ, for the population. Most researchers want to know how accurately the value of the sample mean represents the value of the unknown population mean. 1.96 _ One of the most common statistical problems is to generalize from a set of sample data statistics (to make an "educated guess") about the value of the population parameters. If one were to take a random sample of 1000 women in this age group how many would we expect in our sample to be below -1.6 z-scores? When you move out + and - for the following z-scores on either side of the mean, what percentage of the normal distribution (or percentage of the sampling distribution) do you "capture" or account for? (You will need the TABLE of z-scores to do this.) z-score Percent of ND "captured" 3. What percent of women in this age group are taller than 64 inches? Taller than 66.5 inches? Shorter than 59 inches? c. Draw a normal curve for this distribution, with the scale on the horizontal axes indicating the heights at each of the major deviations. Assume the heights of women 18 to 24 are approximately normally distributed with μ=64 inches and σ=2.5 inches. _ How about the proportion above +2.05z? _ How about below +2.05z? _ Here’s how the normal curve can be used to approximate proportions in a large population: 2. What’s the difference? Once you have mastered the z-score table, use it to find the proportion (percentage) under the normal curve that would be determined by the center (the mean) and ☑.25 z. Use the attached z-score table, locate the z-score for 1.0 and compare the area described in the table to your answer to 1.a. The z-score for 1 standard deviation is +1z and – 1z. within 3 standard deviations from the mean _ Z-scores are used as an all-purpose calibration for the positions along the baseline of the normal curve, because they can be used without any mention of the measurement being taken for whatever variable is being described from the population. within 2 standard deviations from the mean _ c. within 1 standard deviation from the mean _ b. Find the picture and determine the proportions (percentages) under the curve which fall: a. The normal distribution or normal curve is pictured in Williams'. 5) Relationships between the Sample, a Sampling Distribution and the Population 1. Download The Normal Distribution: Worksheet | N 1 and more Health sciences Exams in PDF only on Docsity!The Normal Distribution: Worksheet (Covered in class, but also read Williams, Chap.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |