Your mood gets more positive after working out because you experience

Emily Balcetis suggests that most Americans find their New Year’s Eve resolutions are broken by

When you investigate a newly discovered DNA polymerase from a deep sea microbe and you find that it has an error rate of 1 mistake in every 106  bases copied. However, the overall mutation rate is much lower. This is most likely because:

3.1 What is meant by the term ecosystem (line 3)?   (2)

  Use only if needed

1.2 Water pollution can occur if sewage enters a river. Explain the biological consequences of sewage pollution on a river ecosystem. (6)

Pollution can occur in the atmosphere and in rivers. Carbon monoxide can pollute the atmosphere.   1.1 Describe the effects of carbon monoxide pollution on humans.   (3)

3.4 Suggest how scientists are able to find the percentage of coral that has died in a section of the reef. (3)

Use the normal approximation to find the indicated probability. The sample size is n, the population proportion of successes is p, and X is the number of successes in the sample. n = 83, p = 0.35: P(X ≤ 27)

The following histograms each illustrate a sample. Which sample can be treated as approximately normal?