K Assume that adults have IQ scores that are normally distributed with a mean of 97.6 and a standard deviation 15.8. Find the first quartile Q₁, which is the IQ score separating the bottom 25% from the top 75%. (Hint: Draw a graph.) The first quartile is (Type an integer or decimal rounded to one decimal place as needed.)

K Assume that adults have IQ scores that are normally distributed with a mean of 99 and a standard deviation 19.3. Find the first quartile Q₁, which is the IQ score separating the bottom 25% from the top 75%. (Hint: Draw a graph.) The first quartile is. (Type an integer or decimal rounded to one decimal place as needed.)

The frequency distribution was obtained using a class width of 0.5 for data on cigarette tax rates. Use the frequency distribution to approximate the population mean and population standard deviation. Compare these results to the actual mean u = $1.481 and standard deviation a = $0.971. E Click the icon to view the frequency distribution for the tax rates. The population mean is S. (Round to three decimal places as needed.) Frequency distribution cigarette tax rates - X The population standard deviation is S (Round to three decimal places as needed.) Tax Rate 0.00-0.49 0.50-0.99 1.00-1.49 1.50-1.99 2.00-2.49 2.50-2. 99 3.00-3.49 3.50-399 4.00 4.49 Frequency O Compare these results to the values found using the actual data. 14 O A. The grouped values are both slightly larger. O B. The grouped values are both slightly' smaller. O C. The grouped mean is slightly larger, while the grouped standard deviation is slightly smaller. 17 O D. The grouped mean is slightly smaller, while the…

instructor gives a 100-point examination in which the grades are normally distributed. The mean is 66 and the standard deviation is 5. If there are 5% A's and 5% F's, 15% B's and 15% D's, and 60% C's, find the scores that divide the distribution into those categories. Round the cutoff scores to the nearest whole number. Round intermediate z-value calculations to 2 decimal places. A:_- B: C: D: --- F: _-_

Refer to the data set in the accompanying table. Assume that the paired sample data is a simple random sample and the differences have a distribution that is approximately normal. Use a significance level of 0.05 to test for a difference between the weights of discarded paper (in pounds) and weights of discarded plastic (in pounds). E Click the icon to view the data. In this example, Hg is the mean value of the differences d for the population of all pairs of data, where each individual difference d is defined as the weight of discarded paper minus the weight of discarded plastic for a household. What are the null and alternative hypotheses for the hypothesis test? O A. Ho: Ha = 0 H,: Ha #0 O B. Ho: Ha #0 H1: Hd =0 O C. Ho: Ha #0 O D. Ho: Ha = 0 H1: Hd 0

The amount of caffeine in a sample of five-ounce servings of brewed coffee is shown in the histogram. Make a frequency distribution for the data. Then use the table to estimate the sample mean and the sample standard deviation of the data set. W Click the icon to view the histogram. .. Complete the table. Round values to the nearest tenth as needed. Graph/chart f Midpoint x xf 70.5 Ay 30- 25- 24 20- |14 15- 10- 17 5- X 48.5 70.5 92.5 114.5 136.5 158.5

Refer to the data set in the accompanying table. Assume that the paired sample data is a simple random sample and the differences have a distribution that is approximately normal. Use a significance level of 0.10 to test for a difference between the weights of discarded paper (in pounds) and weights of discarded plastic (in pounds). Click the icon to view the data In this example, Hg is the mean value of the differences d for the population of all pairs of data, where each individual difference d is defined as the weight of discarded paper minus the weight of discarded plastic for a household. What are the null and alternative hypotheses for the hypothesis test? O A. H9: Ha =0 H1: Ha 0

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K Assume that adults have IQ scores that are normally distributed with a mean of 101.5 and a standard deviation 20.1. Find the first quartile Q₁, which is the IQ score separating the bottom 25% from the top 75%. (Hint: Draw a graph.) The first quartile is (Type an integer or decimal rounded to one decimal place as needed.)

Find and interpret the z-score for the data value given. The value 254 in a dataset with mean 186 and standard deviation 25 Round your answer to two decimal places. The value is i standard deviations the mean.