2/8 (Friday) Standard Deviation cont’d Example: Amount of money earned by new immigrants Sample: 12‚ 15‚ 16‚ 20‚ 25‚ 36‚ 40 Step 1: Find the mean * x̄=164/7 * mean is 23.4 Step 2: Find how much each observation deviates from the mean * 12 - 23.4 = -11.4 * 15 – 23.4 = -8.4 * 16 – 23.4 = -7.4 * 20 – 23.4 = -3.4 * 25 – 23.4 = 1.6 * 36 – 23.4 = 12.6 * 40 – 23.4 = 16.6 * Note: all observations below mean will be negative‚ all above will be positive Step
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18. Based on a simple random sample of one hundred an analyst estimates the average hourly wage earned by workers in a city to be $30 and computes the margin of error to be $5. Can we conclude from this that most workers there earn between $25 and $35 per hour? Is the right interpretation for the margin of error? 23. Polls showed the two main candidates in the 2004 presidential election were nearly tied on the day before the election. To predict the winner a newspaper would like to have a poll
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Progress Task Eassy "Being a manager in today ’s dynamic workplace provides many challenges. Describe and discuss the challenges and rewards of being a manager in a contemporary organisation". Managers face varieties of challenge in their job. If a manager had a strong goal to be successful‚ challenges are the necessary parts of their job. Manager need to have three essential skills for without these skills‚ effectiveness can not be realized
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Module 1 Suppose you hear an "old-timer" say‚ "Why‚ in my day‚ kids were much more respectful and didn’t cause as much trouble as they do nowadays!" Formulate a hypothesis related to this statement that you could test. How would you test it? The old-timer are the older person in their 70s or 80s at this time. I would compare the age when this old timer is raising his own children . what actually age he may be‚ let say‚ 25 years old if he was born in 1940 by the year 1965 to determine respectfulness
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Chapter 3 Fluid Statics: Definitions Statics: ∑F = 0. In statics we have only pressure as surface force and weight as body force. Thus‚ when fluids are still‚ the pressure is balanced by the fluid weight. No relative motion between adjacent fluid layers. Shear stress is zero Only _______ can be acting on fluid surfaces Gravity force acts on the fluid (____ force) Applications: Pressure variation within a reservoir Forces on submerged surfaces Buoyant forces 9/4/2013 1 Pressure Pressure is defined
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1. A density curve consists of a straight line segment that begins at the origin (0‚ 0) and has slope of 1. a. Sketch this density curve. What are the coordinates of the right endpoint of the segment? (Note that the right endpoint should be fixed so that the total area under the curve is 1. This is required for a valid density curve.) b. Determine the median‚ the first quartile (Q1)‚ and the third quartile (Q3). c. Relative to the median‚ where would you expect the mean of the distribution to lie
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Reasons Statistics Are Important Tabatha I. Weekley BUS500 Research Paper SIU with Professor Morgan “Statistics is defined as a branch of mathematics dealing with the collection‚ analysis‚ interpretation‚ and presentation of masses of numerical data.” (m-w.com) Or‚ mathematical equations used to figure out what is happening in the world. So‚ why do we use statistics on a daily basis and how are they important? Statistics shape your life whether you know it or not. We use them in weather forecasts
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Final Examination Name: Course: Date: Final Examination in Statistics (M.A.Ed./M.A.N.) 1.The scores of 15 masteral students in Statistics were 80‚85‚78‚90‚91‚98‚95‚98‚95‚74‚71‚72‚98‚99‚and 87. Find the measures of central tendency‚ the range‚ the variance‚ and the standard deviation. 2. In the performance evaluation of teachers‚ if the dean’s evaluation is given a weight of 5‚ self-evaluation is 2‚ peer’s evaluation is 2‚ and student’s evaluation is 1 and the teacher’s
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08 ETHE AUSTRALIAN NATIONAL UNIVERSITY SCHOOL OF FINANCE AND APPLIED STATISTICS First Semester Examination 2010 QUANTITATIVE RESEARCH METHODS (STAT1008) Writing Period: 3 hours duration Study Period: 15 minutes duration Permitted Material: Non-programmable calculator‚ dictionary and 1 A4 page with notes on both sides Instructions to Candidates: • Attempt ALL questions. • Each question is of equal mark value. • Start your solution to each question on a new page. • To ensure full marks
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1) Suppose that an independent laboratory has tested trash bags and has found that no 30-gallon bags that are currently on the market have a mean breaking strength of 50 pounds or more. On the basis of these results‚ the producer of the new‚ improved trash bag feels sure that its 30-gallon bag will be the strongest such bag on the market if the new trash bag’s mean breaking strength can be shown to be at least 50 pounds. The mean of the sample of 40 trash bag breaking strengths in Table 1.9 is x=50
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