STATS+167+Week+4+-+Individual+Assignment+-+Distribution,+Hypothesis+Testing,+and+Error+Worksheet[1]

# STATS+167+Week+4+-+Individual+Assignment+-+Distribution,+Hypothesis+Testing,+and+Error+Worksheet[1]

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Distribution, Hypothesis Testing, and Error Worksheet STAT/167 Version 2 1 University of Phoenix Material Tiffany Bush Adapted from Biostatistics for the Biological and Health Sciences faculty materials with permission from Pearson Addison-Wesley.

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Distribution, Hypothesis Testing, and Error Worksheet STAT/167 Version 2 2 Distribution, Hypothesis Testing, and Error Worksheet Answer the following questions. For questions requiring material from Statdisk, make sure to turn labels on, take a screen capture (CTRL-Print Screen on most Windows-based computers), and paste the image into the worksheet. Crop the image as appropriate. 1. Describe a normal distribution in no more than 100 words (0.5 point). A normal distribution is a continuous random variable distribution which has the mean and median same and the standard deviations are apart from the mean in the probabilities that go with the empirical rule. The normal distribution is continuous, and has only two parameters - mean and variance. The mean can be any positive number and variance can be any positive number (can't be negative - the mean and variance), so there are an infinite number of normal distributions. The shape of the distribution is symmetrical and bell-shaped (bell curve). Use this information to answer questions 2-4. Following a brushfire, a forester takes core samples from the ten surviving Bigcone Douglas-fir trees in a test plot within the burn area, and a dendrochronologist determines the age of the source trees to be as follows (in years): 15 38 48 67 81 83 94 102 135 167 2. Construct a normal quantile plot in Statdisk, show the regression line, and paste the image into your response. Based on the normal quantile plot, does the data above appear to come from a population of Bigcone Douglas-fir tree ages that has a normal distribution? Explain (0.5 point). The normal quantile plot is approximately linear, so the data points are some what normal. 3. Calculate the sample mean and standard deviation for the age of Bigcone Douglas-fir trees based on the data above. If this accurately represents the population mean and standard deviation for the age of surviving Bigcone Douglas-fir trees in the burn area, what is the probability that a randomly selected surviving Bigcone Douglas-fir tree from the burn area will be 111 years old or less? Round to the nearest hundredth (0.5 point). Mean = 83 Standard deviation = about 45.19 The probability is 73%. 4. Calculate the sample mean and standard deviation for the age of Bigcone Douglas-fir trees based on the data above. If this accurately represents the population mean and standard deviation for the age of surviving Bigcone Douglas-fir trees in the burn area, what is the probability that a randomly selected surviving Bigcone Douglas-fir tree from the burn area will be less than 0 years old? Round to the nearest hundredth. Based on this result, is it logical to assume that the population of age of surviving Bigcone Douglas-fir trees in the burn area is normally distributed with the parameters identified. Why or why not
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STATS+167+Week+4+-+Individual+Assignment+-+Distribution,+Hypothesis+Testing,+and+Error+Worksheet[1]

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