Question

A research wants to determine if pre-natal exposure to the hormones in birth control pills alters the sex makeup of midshipman fish populations (which are typically half male and half female). Specifically, the researcher wishes to test the hypothesis that exposure to hormones will increase the number of females in the population. The researcher exposes a group of pregnant midshipman fish to birth control hormones and records the sex of the first 6 offspring birthed. They then observe that 4 are female. Use a sign test to test the indicated hypothesis. What is the value of "significance"

Answer 1

To determine the significance of the hypothesis that pre-natal exposure to hormones increases the number of females in midshipman fish populations, a sign test can be used to calculate the probability of observing 4 or more females out of 6 births. If this probability is less than the significance level, the hypothesis is supported.

Step-by-step explanation:

To test the hypothesis that exposure to hormones will increase the number of females in the midshipman fish population, a sign test can be used. In this case, the researcher exposed a group of pregnant midshipman fish to birth control hormones and recorded the sex of the first 6 offspring. Out of the 6 offspring, 4 were female. To calculate the significance using a sign test, we determine the probability of observing 4 or more females out of 6 births if the population sex makeup is 50% female. If this probability is less than a predetermined significance level (usually 0.05), we reject the null hypothesis and conclude that the exposure to hormones increases the number of females in the population.