Final answer:
The probability distribution for the proportion of voters supporting a school levy increase can be approximated by a normal distribution. The mean and standard deviation can be determined using the given information. The -2 standard deviations, mean, and +2 standard deviations can then be calculated.
Step-by-step explanation:
The probability distribution for the proportion of the polled voters that support a school levy increase can be approximated by a normal distribution. To determine the mean and standard deviation of this distribution, we use the given information that 55% of voters support the school levy increase. This means that the mean (μ) is 0.55 and the standard deviation (σ) can be calculated as follows:
σ = √(p(1-p)/n)
Where p is the proportion of voters supporting the school levy increase (0.55) and n is the number of voters polled (195). Using this formula, we can find that the standard deviation is approximately 0.0427. Now, we can answer the questions based on this normal distribution.
- The -2 standard deviations from the mean is μ - 2σ = 0.55 - 2(0.0427) = 0.4646
- The mean is μ = 0.55
- The +2 standard deviations from the mean is μ + 2σ = 0.55 + 2(0.0427) = 0.6374