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Statistics help please?

You are a statistician at a local television station, and you have been asked to evaluate the performance of the meteorological team (i.e. the weather people). You obtain temperature measurements for actual high and low temperatures and the predicted high and low temperatures for 31 randomly selected days from the current year. Using the data to support your evaluation, answer the following questions regarding the accuracy of temperature prediction by the meteorological team.

1). Evaluate the weather team's ability to accurately predict low temperatures. Using the appropriate hypothesis test, is there sufficient evidence that a predicted temperature will, on average, differ from the actual temperature? (Hint: Create another variable DLOW = Predicted Low - Actual Low. If there is, on average, no significant difference between predicted and actual low temperatures, what should the mean DLOW equal?)

(35 points)

a. State the null hypothesis and the alternative hypothesis. Name the type of test you will you use, and justify why you have selected this particular

test.

b. Perform the appropriate hypothesis test. Use a significance level of

α=0.05. Give the test statistic, the critical value, and the p-value.

c. What are your conclusions? Based on the results from your hypothesis test, does the weather team generally do a good job in accurately

predicting low temperatures?

Update:

At the very least i wanna know which test equation to use

2 Answers

Relevance
  • bpiguy
    Lv 7
    1 decade ago
    Favorite Answer

    To do this one, take the provided hint; that is, create a new variable DLOW = Predicted Low - Actual Low. Get the mean and variance/standard deviation of this variable. If the weather forecasters are doing a good job, the mean of DLOW should be zero.

    To test that, your null hypothesis is that the mean is <not> zero, and you'd like to reject that hypothesis. The alternative hypothesis is that the mean <is> zero.

    You should to a two-tailed z-test and, for a 95% confidence level, look 2σ in each direction.

    If you do all that, you'll have all your answers.

  • 1 decade ago

    Big problem: data missed!

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