You want to find the average GPA at Adelphi, so you decide to perform a study. You went outside the UC and screamed at people going to lunch, "What's your GPA?" You copied down the first 50 people to answer you. Survey of Statistics Lab Data 1) Discuss the sampling technique(s) used. Do you feel that they could have been improved? Explain. 1.04 2.03 4.14 1.05 2) Display the data in a histogram with the following intervals: 0-1, 1-2, 2-3, 3-4,4-s 0.58 4.02 3.67 2.06 0.67 3) Calculate the mean, median, mode, and range for the study. Also calculate the variance and the sample standard deviation. (Use your calculator.) 3.29 2.23 4) Construct a box and whisker piot of the data. What are the boundaries for the outliers? 3.83 0.24 1.73 5) (a) is it appropriate to use a student's t distribution to compute a confidence interval for the population mean ? 2.53 3.75 2.65 4.98 3.63 (b) Find a 95% confidence interval for " (Show all work and state formulas used.) 4.03 (c) What does the confidence interval mean in the context of this problem? 0.57 2.16 1.06 1.78 0.49 How large of a sample is needed if we wish to be 99% confident that the sample mean is within 25 pts of the population mean score? For this problem, assume that we know that the population standard deviation σ is 1.5. 0.03 4.22 3.21 3.67 1.61 7) Suppose that Adelphi boasts that it has an average GPA of 3.0. Perform a hypothesis test with a level of significance of .05, and anethefHtHeerefeieriemeeef you performed with 50 students is enough to refute this claim. Your final answer must be written in full sentences and reference the math that you performed. (You may assume that the population standard deviation ơ is 1.5.) e4, to see if the study 4.14 0.42 4.31 3.62 4.14 4.09 2.16 1.68 0.99 3.76 0.29 0.85
Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.
Mean, Median, Mode
It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
Avarege GPA questions. Data include.


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