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# if a data set has a mean and the variance what is the z score corresponding to

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r if my data won’t work and I need to set up a new experiment
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first 2 weeks. 50 people who joined the programme are sampled, their weight loss is 9 pounds with a standard deviation of 2.8 pounds. Can we conclude at the .05 level that a person joining the programme will lose less than 10 pounds? (2) The following is a random sample of 90-day futures prices in dollars for 1 troy oz. of silver from The Wall Street Journal issues in May and June of 1997: 4.74, 4.77, 4.87, 4.91, 4.83, 4.72, 4.92, 4.86, 4.97, 4.71, 4.90, 4.93, 4.75, 4.88, 4.79, 4.83, 4.89. Required: a. Calculate the mean b. Median c. Standard deviation of the 90-day future price of silver data (3) A mining company needs to estimate the average amount of copper ore per ton mined. A random sample of 50 tons gives a sample mean of 146,75 pounds. The population standard deviation is assumed to be 35.2 pounds. Required: a. Give a 95% confidence interval for the average amount of copper in the population of tons mined. b. Give a 90% confidence interval for the average amount of coper per ton c. Give a 99% confidence interval for the average amount of coper per ton (4) An e-commerce Website gets 2,385 visitors on a particular day. Among these, 1790 visitors explore the products by looking at more pages at the site. Among these 1790 visitors who explore the products, 387 make a purchase. Required: a. If a visitor chosen at random from all those who visited the site, what is the probability that the visitor explored the products b. If a visitor is chosen at random from all those who visited the site, what is the probability that the visitor made a purchase. c. If a visitor is chosen at random from all those who explored the products, what is the probability that the visitor made a purchase. d. Which of the preceding three probabilities is relevant to the design of the home page that leads to product page.
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ly buy stock in companies that are ranked in the 80thpercentile or above in terms of dividends paid in the previous year. You are looking at a company that ranked 5 of 70 companies that paid dividends in 2019. a. Will this company qualify for your portfolio? b. If you had the data on the total dividends paid by each of the 70 companies, which measure of average would be the most meaningful –mean, median, midrange, or mode? Explain
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ete parts​ (a) through​ (c) below. Year 2000 2005 2007 2009 2011 2013 2015 Assets 15 40 52 79 117 151 199 ​(a) Find an exponential model of the form ​f(t)y0bt for these​ data, where t=0 corresponds to the year 2000. If you do not have suitable​ technology, use the first and last data points to find a function. If you have a graphing calculator or other suitable​ technology, use exponential regression to find a function. The exponential model for the data is ​f(t)= . ​(Round to three decimal places as​ needed.)
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hin a free demo session as I have my answers, but just want to confirm them, that would be greatly appreciated. Question 1: A block of mass M = 0.10 kg is attached to one end of a spring with spring constant k = 100 N/m . The other end of the spring is attached to a fixed wall. The block is pushed against the spring, compressing it a distance x = 0.04 m . The block is then released from rest, and the block-spring system travels along a horizontal, rough track. Data collected from a motion detector are used to create a graph of the kinetic energy K and spring potential energy Us of the system as a function of the block's position as the spring expands. How can the student determine the amount of mechanical energy dissipated by friction as the spring expanded to its natural spring length? Question 2: The Atwood’s machine shown consists of two blocks connected by a light string that passes over a pulley of negligible mass and negligible friction. The blocks are released from rest, and m2 is greater than m1. Assume that the reference line of zero gravitational potential energy is the floor. Which of the following best represents the total gravitational potential energy U and total kinetic energy K of the block-block-Earth system as a function of the height h of block m1? Question 3: A 2 kg block is placed at the top of an incline and released from rest near Earth’s surface and unknown distance H above the ground. The angle θ between the ground and the incline is also unknown. Frictional forces between the block and the incline are considered to be negligible. The block eventually slides to the bottom of the incline after 0.75 s. The block’s velocity v as a function of time t is shown in the graph starting from the instant it is released. How could a student use the graph to determine the total energy of the block-Earth system? Question 4: A block slides across a flat, horizontal surface to the right. For each choice, the arrows represent velocity vectors of the block at successive intervals of time. Which of the following diagrams represents the situation in which the block loses kinetic energy?
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bacteria). Obligatory anaerobes require absence of oxygen. You are researching how a facultative anaerobe transitions from anaerobic to aerobic respiration along the length of the human intestine (small and large intestine), where oxygen levels – and with them respiration - vary from atmospheric levels of oxygen (aerobic respiration) to no oxygen (anaerobic respiration). You grow cultures of a facultative anaerobic bacteria in flasks with different levels of oxygen that mimic the conditions in the 7.5m long human intestines and collect data on the growth rates of the bacteria (number of bacterial colonies) under the different conditions. Time food spends in the small intestine, 2.5m long, is 4 hrs. The time taken for food to pass through the entire length of the intestine is between 24 and 72 hrs. To determine oxygen levels in your flasks, you use the ratio of oxygen to nitrogen, which you vary between 0 (no oxygen) and 0.25 (atmospheric levels of oxygen). You assume that for conditions where r<0.01 your bacteria will be obligatorily anaerobic, and aerobic respiration will be observed from r=0.05. If the oxygen ratio goes from 0.25 to 0 over 7.5 m, and rO2 = 0.25 – 0.03x (x=distance along the intestine) describes the relationship between oxygen ration and the length of path travelled by the bacteria in the intestine, how long will it take bacteria to pass from the small into the large intestine? Explain how you arrived at your estimate.
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your research question. Final Mission: You will use the given dataset to develop a research question, create background on the topic related to the research question, and complete an analysis of the data to answer that research question. Guidelines ➢ Use no more than 12 slides with a voice-over description for each slide. You may be creative with background and animation for the slide show but remember that it is the content that is most important (and animation, etc. can greatly increase your file size). ➢ Include an introductory slide that states your name, credentials, and title of your presentation. ➢ Present your research question. ➢ Identify the appropriate statistical test to answer the research question. o Identify your variables of interest. o Identify how they are measured and match them to the appropriate statistical test. ➢ Identify and evaluate appropriate assumptions to meet the test. o Each statistical test comes with a set of assumptions that must be met in order to use the test; conditions that must be satisfied before using the test. o Explain the assumptions and show how they have been met as well as how you would “fix” them if they were “broken.” ➢ Provide a justification for all the choices you made in the decision of which statistic to use and explain the necessary tests associated with it in terms someone not familiar with it would understand. ➢ Use APA format for any citations within the PowerPoint.
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