statistics

posted by .

A random sample of 80 youths and a second random sample of 120 adults showed that 18 of the youths and 10 of the adults had been ticketed for careless driving. Use a 1% level of significance to test the claim that youth have a higher proportion of careless drivers than adults do. state the null and alternative hypothesis

  • statistics -

    You will need to use a formula for a binomial proportion two-sample z-test.

    Proportion of adults = 10/120 = .083
    Proportion of youths = 18/80 = .225

    Use these proportions in the formula.

    Null:
    Ho: pY = pA (A = adults; Y = youths)
    Alternative:
    Ha: pY > pA

    This will be a one-tailed test at .01 level of significance. (Use a z-table to determine the critical or cutoff value to reject the null.) If the test statistic calculated from the formula exceeds the critical value from the table, reject the null and conclude pY > pA. If the test statistic does not exceed the critical value from the table, do not reject the null (there is no difference).

    I hope this brief explanation will help get you started.

  • statistics -

    (b) How many would you expect to be taller than 160 cm?

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Statistics: Two Sample Population Confidence Inter

    Two Sample Population Confidence Interval: Before an intensive TV advertising campaign, the producers of Nike athletic shoes find that 30 of a random sample of 217 upper-income adults were aware of their new leisure shoe line. A second …
  2. Statistics

    A test of 60 youths and 140 adults showed that 22 of the youths and 10 of the adults were careless drivers. Use a 1% level of significance to test the claim that the youth percentage of careless drivers is higher than the adult percentage. …
  3. Statistics

    Data in 1980 showed that about 48% of the adult population had never smoked cigarettes. In 2004, a national health survey interviewed a random sample of 5000 adults and found that 54% had never been smokers. Create a 95% confidence …
  4. statistics

    A nationwide study indicated that 27% of adults said that chocolate was their favorite ice cream flavor. A simple random sample of 150 adults is obtained. A.) Describe the sampling distribtuion of p, the sample proportion of adults …
  5. Statistics

    2. In 2009 a random sample of 70 unemployed people in Alabama showed an average weekly benefit of $199.65. In Mississippi, for a random sample of 65 the number was $187.93. Assume population standard deviations of $32.48 and $26.15 …
  6. Statistics

    The Centers for Disease Control (CDC) collects yearly statistics on drinking behavior in the United States by surveying a random sample of U.S. adults. The following data display the percent of adults aged 18 years and over who had …
  7. Statistics

    Daily water intake (including water used in drinks such as coffee, tea and juice) for Canadian adults follows a normal distribution with mean 1.86 litres and standard deviation 0.29 litres. (a) Can you calculate the probability that …
  8. Applied Stats

    Based on the data collected by the National Centre for health Statistics and made available to the public in the Sample Adult database, it was found that the percentage of adults who have at some point in their life been told that …
  9. Statistics

    Based on data collected by the National Center for Health Statistics and made available to the public in the Sample Adult database (A-5), an estimate of the percentage of adults who have at some point in their life been told they have …
  10. Statistics

    In a study by Peter D. Hart Research Associates for the Nasdaq Stock Market, it was determined that 20% of all stock investors are retired people. In addition, 40% of all adults invest in mutual funds. Suppose a random sample of 25 …

More Similar Questions