Last updated 24 October 1995

Statistics 343
Autumn, 1995

Homework 3
Due Tuesday, 31 October 1995

Brief Report #1 The concentration of follicle stimulating hormone (FSH) can be measured through a bioassay (an indirect measurement technique). The idea behind the assay is that when FSH is added to a certain culture, an amount of another substance, estrogen, is produced that is proportional to the FSH level. As a result, the amount of FSH can be determined by measuring estrogen production.

There is a problem with this bioassay, however. When the goal is to determine the FSH levels in human serum (that is human blood without the red and white blood cells), some substances in the serum inhibit estrogen production, so that the bioassay is not correct. An experiment was done to see if polyethylene glycol (PEG) could be added to the serum before testing for FSH, in the hope that PEG would bind chemically to some of the substances that reduce estrogen production. In this case, the estrogen output would more accurately reflect the FSH concentration in the serum sample.

Three treatments were applied to prepared cultures: no serum, PEG-treated serum, and untreated serum. To each of these cultures, one of eight doses of FSH was added: 4, 2, 1, 0.5, 0.25, 0.125, 0.06 or 0.0 mIU/microL. For each combination of serum-type and dose, there were three cultures. After letting each culture grow for three days, each culture had its estrogen content measured by a technique called radioimmunoassay. The data in the table below give the results (units are nanograms of estrogen per milliliter). These data are available in machine-readable form in the file FSH.DAT in the directory Other Data Sets. [Source: Rice, 1995, 482]

Analyze these data. The purpose of the investigation is to determine the degree to which PEG is effective at removing the inhibitory substances from the serum.

  Dose      No      PEG   Untreated    Dose     No       PEG   Untreated
          Serum    Serum      Serum            Serum    Serum      Serum

  0.00   1814.4    372.7     1745.3    0.50  14538.8   6074.3     4471.9
  0.00   3043.2    350.1     2470.0    0.50  14214.3  12273.9     2772.1
  0.00   3857.1    426.0     1700.0    0.50  16934.5  14240.9     5782.3
  0.06   2447.9    628.3     1919.2    1.00  19719.8  17889.9    11588.7
  0.06   3320.9    655.0     1605.1    1.00  20801.4  11685.7     8249.5
  0.06   3387.6    700.0     2796.0    1.00  32740.7  11342.4    18481.5
  0.12   4887.8   1701.8     1929.7    2.00  16453.8  11843.5    10433.5
  0.12   5171.2   2589.4     1537.3    2.00  28793.8  18320.7     8181.0
  0.12   3370.7   1117.1     1692.7    2.00  19148.5  23580.6    11104.0
  0.25  10255.6   4114.6     1149.1    4.00  17967.0  12380.0    10020.0
  0.25   9431.8   2761.5      743.4    4.00  18768.6  20039.0     8448.5
  0.25  10961.2   1975.8      948.5    4.00  19946.9  15135.6    10482.8
Write a brief report summarizing and documenting your conclusions. Submit three copies of your report together with one copy of the report submission form. Two of these copies will be distributed to other students in the class, who will comment on the contents and presentation of your report.

You must follow the instructions on the report submission form. NOTE in particular that your report is not to exceed one side of one page (including any figures or tables).