Question

Question No 4

A music industry professional claims that the standard deviation of the amount of money that an average teenager spends per month on music is less than $10. The sample standard deviation is estimated to be $14. The music professional surveys 23 students and finds that the mean spending is $37. Test the claim by using α=0.05 by traditional method.

Question No 5

A report by the Gallup Poll stated that on average a woman visits her physician 5.8 times a year. A researcher randomly selects 20 women and obtained these data. The population standard deviation is 2

3    2    1    3    7     2     9     4     6     6    8   0   5   6   4    2   1   3   4    1

At α= 0.01 can it be concluded that the average is still 5.8 visits per year? Use the traditional method.

Answer 1

4)

    (1)null and alternative hypothesis are

  

Ho: 0=10 На: 0<10

(2) Rejection Region Based on the information provided, the significance level is a = 0.05, and the the rejection region for this left-tailed test is R = {x?: x² < 12.338). (3) Test Statistics The Chi-Squared statistic is computed as follows: (n-1)s_(23-1). 196 100 43.12 (4) Decision about the null hypothesis Since it is observed that x = 43.12 > x = 12.338, it is then concluded that the null hypothesis is not rejected.

     (5) conclusion:

    Therefore, there is not enough evidence to claim that the standard deviation is less than 10, at the 0.05 significance level.

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