Unit Test Unit Test Review
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Read the passage about bird food and bird watching.
Noted scientist Dr. Elsa Birde described the effect of adding a mixture of dried apples and raisins to the
previous feed of sunflower seeds, millet, thistle seed, and cracked corn in bird feeders in her yard. Over three
years, Dr. Birde observed that the new mixture increased the number of songbirds at her feeders, especially
during the months of April and May. As she has done for several years, Dr. Birde recorded, at the same time
each day, the number of birds at each of her four feeders. She noted that the third year using the mixture
coincided with the largest increase. There was a twenty-five percent increase in the number of songbirds over
times when this mixture was not used. Dr. Birde also noted that in the tņird year she used a specific ratio of
the ingredients, carefully measuring, which she had not done in previous years. The third year also had a
warmer than normal spring, and a construction project began in a neighborhood near Dr. Birde's. Dr. Birde is
now going to produce this formula for sale and advertise to customers that they may see the same twenty-
five percent increase in songbirds at their feeders.
Dr. E. Birde, Journal of Scientific Bird Feeding
Which scientific claim can be made?