MS 150 Statistics Fall 2001 Midterm

relationshipsq03.gif (3386 bytes)

For the above six graphs circle the correct word applicable to that graph in the column:

Shape of correlation
A none | linear-positive | linear-negative | non-linear
B none | linear-positive | linear-negative | non-linear
C none | linear-positive | linear-negative | non-linear
D none | linear-positive | linear-negative | non-linear
E none | linear-positive | linear-negative | non-linear
F none | linear-positive | linear-negative | non-linear
  1. Measures of Central Tendency
    Rainfall in inches per year for Pohnpei 1994 to 1999 x
    163
    169
    154
    173
    128
    196
    1. Find the sample size n: ______
    2. Find the minimum: ______
    3. Find the maximum: ______
    4. Find the range: ______
    5. Find the median: ______
    6. Find the mode: ______
    7. Find the sample mean xbar.gif (842 bytes): ______
    8. Find the sample standard deviation sx: ______
    9. Find the sample coefficient of variation CV:______
  2. Linear Regression
    Year (Year 0 is 1994) x Total Rainfall in inches in Pohnpei y
    0 163
    1 169
    2 154
    3 173
    4 128
    5 196
    1. For the data above, determine the slope m = ________
    2. For the data above, determine the y-intercept = ________
    3. Determine the correlation coefficient r = ________
    4. Determine the coefficient of determination  = ________
    5. What would be the projected rainfall amount in 2000? ________________
    6. Why is 1998 (year 4) so much lower than the other years (Use the back to have enough space to write out your answer)?
  3. Dependent Probabilities
    Number of Females (F) Number of Males (M) Sums
    Students who prefer chicken for lunch (C) 10 15 ______
    Students who prefer fish for lunch (S) 20 15 ______
    Sums ______ ______ ______
    1. Determine the probability that a member of sample is female: P(F) = ______
    2. Determine the probability that a member of sample is female and prefers chicken: P(F and C) = _____
    3. Determine the probability that a member of sample is female or prefers fish: P(F or S)
    4. Determine P(F, given C) = _______________
    5. Which do you prefer, chicken or fish for lunch?
  4. Probability Distributions
    Total inches of rain in Pohnpei per Month (Class Upper Limit) x Frequency (Number of months with rainfall amounts between the CLL and CUL) Relative Frequency P(x) x*P(x)
    6 8 _______ _______
    12 17 _______ _______
    18 35 _______ _______
    24 8 _______ _______
    30 6 _______ _______

    Sum:

    		 _______ _______ _______
    1. Calculate the relative frequencies P(x) and record the relative frequencies in the table above.
    2. Sketch a relative frequency histogram on the BACK of this sheet of paper, labeling your horizontal and vertical axes as appropriate.
    3. What is the shape of the distribution?
    4. Calculate the mean value m using the fourth column of the table above. m = _______
Statistic or Parameter Symbol Equations Excel
Square root =SQRT(number)
Sample mean xbar.gif (842 bytes) Sx/n =AVERAGE(data)
Sample standard deviation sx =STDEV(data)
Sample Coefficient of Variation CV 100(sx/xbar.gif (842 bytes)) =100*STDEV(data)/AVERAGE(data)
Slope b =SLOPE(y data, x data)
Intercept a =INTERCEPT(y data, x data)
Correlation r =CORREL(y data, x data)
Coefficient of Determination rē =(CORREL(y data, x data))^2

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