Ask Question
6 May, 20:16

In a certain large city, the mean birth weight of babies is 7.1 pounds with a standard deviation of 1.2 pounds. You believe that in one neighborhood in the city the mean birth weight is different from 7.1 pounds. You sample 95 births and find the mean weight of the sample to be 7.4 pounds. Can the claim be supported to a level of significance of α =.05, test the hypothesis?

+5
Answers (1)
  1. 6 May, 22:03
    0
    No, the claim that the mean birth weight is 7.1 pounds cannot be supported at 0.05 significance level.

    Step-by-step explanation:

    A z-test is used to test the hypothesis because the population standard deviation is known.

    Null hypothesis: The mean birth weight is 7.1 pounds.

    Alternate hypothesis: The mean birth weight is not equal to 7.1 pounds.

    The test is a two-tailed test because the alternate hypothesis is expressed with the inequality not equal to.

    Test statistic (z) = (sample mean - population mean) : (population sd/√n)

    sample mean = 7.4 pounds

    population mean = 7.1 pounds

    population sd = 1.2 pounds

    n = 95

    z = (7.4 - 7.1) : (1.2/√95) = 0.3 : 0.123 = 2.44

    At 0.05 significance level, the critical values from the standard normal distribution table are - 1.96 and 1.96.

    Conclusion:

    Reject the null hypothesis because the test statistic 2.44 falls outside the region bounded by the critical values - 1.96 and 1.96.

    The claim cannot be supported at a 0.05 significance level.
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “In a certain large city, the mean birth weight of babies is 7.1 pounds with a standard deviation of 1.2 pounds. You believe that in one ...” in 📘 Mathematics if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers