Sta - Chapter 2
Determine whether the following statement is true or false. The shape of the distribution shown is best classified as skewed left.
Graphic shown, False.
Determine whether the following statement is true or false. The shape of the distribution shown is best classified as uniform.
Graphic shown, False.
A phlebotomist draws the blood of a random sample of 50 patients and determines their blood types as shown. Complete parts (a) through (f). (a) According to the data, which blood type is most common? (b) According to the data, which blood type is least common? (c) Use the results of the sample to conjecture the percentage of the population that has type O blood. Is this an example of descriptive or inferential statistics? Select the correct choice below and fill in the answer box to complete your choice. (d) Contact a local hospital and ask them the percentage of the population that is blood type O. Why might the result differ? (e) Draw a frequency bar graph. (f) Draw a relative frequency bar graph.
(a) O (b) AB (c) 42%; inferential (d) The results might differ because there is always a chance that the sample surveyed is unlike the population. (e) Graphic shown. (f) Graphic shown.
The pie chart below depicts the beverage size customers choose while at a fast food restaurant. Complete parts (a) through (c). (a) What is the most popular size? What percentage of customers choose this size? (b) What is the least popular size? What percentage of customers choose this size? (c) What percent of customers choose a medium-sized beverage?
(a) XL; 56% (b) Small; 9% (c) 20%
A phlebotomist draws the blood of a random sample of 50 patients and determines their blood types as shown. Construct a relative frequency distribution.
A 0.38 AB 0.08 B 0.12 O 0.42
For ages of hearing-aid patients, state whether you would expect a histogram of the data to be bell-shaped, uniform, skewed left, or skewed right.
Skewed left
The table below shows the tax, in dollars, on a pack of cigarettes in 30 randomly selected cities as of September 2010. Complete parts (a) through (j). (a) Construct a frequency distribution with the first class having a lower class limit of 0 and a class width of 0.50. (b) Construct a relative frequency distribution with the first class having a lower class limit of 0 and a class width of 0.50. (c) Construct a frequency histogram of the data. Choose the correct graph below. (d) Construct a relative frequency histogram of the data. Choose the correct graph below. (e) Describe the shape of the distribution. Choose the correct answer below. (f) Construct a frequency distribution with the first class having a lower class limit of 0 and a class width of 1. (g) Construct a relative frequency distribution with the first class having a lower class limit of 0 and a class width of 1. (h) Construct a frequency histogram of the data. Choose the correct graph below. (i) Construct a relative frequency histogram of the data. Choose the correct graph below. (j) Describe the shape of the distribution. Choose the correct answer below.
(a) 0-0.49 4 0.50-0.99 9 1.00-1.49 5 1.50-1.99 4 2.00-2.49 3 2.50-2.99 2 3.00-3.49 2 3.50-3.99 0 4.00-4.49 1 (b) 0-0.49 0.13 0.50-0.99 0.3 1.00-1.49 0.17 1.50-1.99 0.13 2.00-2.49 0.1 2.50-2.99 0.07 3.00-3.49 0.07 3.50-3.99 0 4.00-4.49 0.03 (c) Graphic shown. (Skewed right) (d) Graphic shown. (Skewed right) (e) Skewed right (f) 0-0.99 13 1-1.99 9 2-2.99 5 3-3.99 2 4-4.99 1 (g) 0-0.99 0.43 1-1.99 0.3 2-2.99 0.17 3-3.99 0.07 4-4.99 0.03 (h) Graphic shown. (Skewed right) (i) Graphic shown. (Skewed right) (j) Skewed right
The following data represent the number of potholes on 35 randomly selected 1-mile stretches of highway around a particular city. Complete parts (a) through (g) below. Table shown. (a) Construct a frequency distribution of the data. (b) Construct a relative frequency distribution of the data. (c) Using the results from part (b), what percentage of the stretches of highway have 3 potholes? (d) Using the results from part (b), what percentage of the stretches of highway have 5 or more potholes? (e) Construct a frequency histogram of the data. Choose the correct answer below. (f) Construct a relative frequency histogram of the data. Choose the correct answer below. (g) Describe the shape of the distribution. Choose the correct answer below.
(a) 1 11 2 5 3 6 4 4 5 4 6 2 7 3 (b) 1 0.31 2 0.14 3 0.17 4 0.11 5 0.11 6 0.06 7 0.09 (c) 17% (d) 26% (e) Graphic shown. (f) Graphic shown. (g) Skewed right
The following data represent the percent of owners of an electronic device that plan to purchase a replacement device within the next 12 months based on a survey of 1100 adults in a certain country. Complete parts (a) through (c). (a) What percent of game console owners plan to buy a replacement device within the next 12 months? (b) If there are 250 million individuals who own a cell phone, how many expect to replace their phone within the next 12 months? (c) If the results of the survey were claimed to indicate that 7.8% of adults in this country who own digital cameras plan to replace their camera in the next 12 months, would you say this statement is descriptive or inferential? Why?
(a) 10.5% (b) 37250000 (c) The statement is inferential, because the survey reports on a sample of the country's population. This claim requires an inference to the population.
A library took a survey to find the age distribution of 50 randomly selected new youth members. The results are shown in the table below. Table shown. (a) Use proportions to construct a relative frequency distribution of the data. (b) What percentage of new youth members are in the 6-8 agegroup? (c) What percentage of the new youth members are age 12 or older?
(a) 3-5 0.06 6-8 0.16 9-11 0.28 12-14 0.36 15-17 0.14 (b) 16% (c) 50%
The data below represent the per capita (average) disposable income (income after taxes) for 25 randomly selected cities in a recent year. Complete parts (a) through (j). (a) Construct a frequency distribution with the first class having a lower class limit of 30,000 and a class width of 6000. (b) Construct a relative frequency distribution with the first class having a lower class limit of 30,000 and a class width of 6000. (c) Construct a frequency histogram of the data. Choose the correct graph below. (d) Construct a relative frequency histogram of the data. Choose the correct graph below. (e) Describe the shape of the distribution. Choose the correct answer below. (f) Construct a frequency distribution with the first class having a lower class limit of 30,000 and a class width of 3000. (g) Construct a relative frequency distribution with the first class having a lower class limit of 30,000 and a class width of 3000. (h) Construct a frequency histogram of the data. Choose the correct graph below. (i) Construct a relative frequency histogram of the data. Choose the correct graph below. (j) Describe the shape of the distribution. Choose the correct answer below.
(a) 30000-35999 13 36000-41999 11 42000-47999 0 48000-53999 1 (b) 30000-35999 0.52 36000-41999 0.44 42000-47999 0 48000-53999 0.04 (c) Graphic shown. (Skewed right) (d) Graphic shown. (Skewed right) (e) Skewed right (f) 30000-32999 4 33000-35999 9 36000-38999 7 39000-41999 4 42000-44999 0 45000-47999 0 48000-50999 0 51000-53999 1 (g) 30000-32999 0.16 33000-35999 0.36 36000-38999 0.28 39000-41999 0.16 42000-44999 0 45000-47999 0 48000-50999 0 51000-53999 0.04 (h) Graphic shown. (Skewed right) (i) Graphic shown. (Skewed right) (j) Skewed right
A phlebotomist draws the blood of a random sample of 50 patients and determines their blood types as shown. Complete parts (a) through (i). (a) Construct a frequency distribution. (b) Construct a relative frequency distribution. (c) According to the data, which blood type is most common? (d) According to the data, which blood type is least common? (e) Use the results of the sample to conjecture the percentage of the population that has type O blood. Is this an example of descriptive or inferential statistics? Select the correct choice below and fill in the answer box to complete your choice. (f) Contact a local hospital and ask them the percentage of the population that is blood type O. Why might the results differ? (g) Draw a frequency bar graph. (h) Draw a relative frequency bar graph. (i) Draw a pie chart.
(a) A 19 AB 4 B 6 O 21 (b) A 0.38 AB 0.08 B 0.12 O 0.42 (c) O (d) AB (e) 42%; inferential (f) The results might differ because there is always variability because the individuals in a. survey may not exactly reflect the makeup of the population. (g) Graphic shown. (h) Graphic shown. (i) Graphic shown.
The following Pareto chart represents the number of freshmen enrolled in six high schools in a school district. Use the chart to answer parts a through c. (a) Which high school has the most freshmen enrolled? (b) Approximately what is the number of freshmen enrolled in Edison High School? (c) How many more freshmen are enrolled at Franklin High School than Creek Hollow High School?
(a) East Lake (b) 900 (c) 50
In a poll, a random sample of 2163 adults (aged 18 and over) was asked, "When you see an ad emphasizing that a product is made in your country, are you more likely to buy it, less likely to buy it, or neither more nor less likely to buyit?" The results of the survey are presented in the side-by-side graph. Complete parts (a) through (d) below. (a) What proportion of 18- to 34-year-old respondents are more likely to buy when made in their country? What proportion of 35- to 44-year-old respondents are more likely to buy when made in their country? (b) What age group has the greatest proportion who are more likely to buy when made in their country? (c) Which age group has a majority of respondents who are less likely to buy when made in their country? (d) What is the apparent association between age and likelihood to buy when made in their country?
(a) The proportion of 18- to 34-year-old respondents is 0.65. The proportion of 35- to 44-year-old respondents is 0.56. (b) 18-34 yrs (c) 55+ yrs (d) As age decreases, likelihood to buy homegrown increases.
A phlebotomist draws the blood of a random sample of 50 patients and determines their blood types as shown. Construct a frequency distribution.
A 18 AB 4 B 6 O 22
What is a bar graph? What is a Pareto chart?
A bar graph is a horizontal or vertical representation of the frequency or relative frequency of the categories. The height of each rectangle represents the category's frequency or relative frequency. A Pareto chart is a bar graph whose bars are drawn in decreasing order of frequency or relative frequency.
The following frequency histogram represents the IQ scores of a random sample of seventh-grade students. IQs are measured to the nearest whole number. The frequency of each class is labeled above each rectangle. Use the histogram to answers parts (a) through (g). (a) How many students were sampled? (b) Determine the class width. (c) Identify the classes and their frequencies. Choose the correct answer below. (d) Which class has the highest frequency? (e) Which class has the lowest frequency? (f) What percent of students had an IQ of at least 130? (g) Did any students have an IQ of 162?
Graphic shown. (a) 200 students (b) The class width is 10. (c) 60-69, 2; 70-79, 3; 80-89, 14; 90-99, 44; 100-109, 52; 110-119, 41; 120-129, 33; 130-139, 8; 140-149, 2; 150-159, 1 (d) 100-109 (e) 150-159 (f) 5.5% (g) No, because there are no bars, or frequencies, greater than an IQ of 160.
An experiment was conducted in which two fair dice were thrown 100 times. The sum of the pips showing on the dice was then recorded. The following frequency histogram gives the results. Use the histogram to complete parts a-e. (a) Which outcome was the most frequent outcome of the experiment? (b) Which outcome was the least frequent? (c) How many times did we observe a 6? (d) Determine the percentage of time a 6 was observed. (e) Describe the shape of the distribution.
Graphic shown. (a) 7 (b) 2 (c) 15 (d) 15% (e) Bell-Shaped
In a relative frequency distribution, what should the relative frequencies add up to?
The relative frequencies add up to 1.
A frequency distribution lists the number ______ of occurrences of each category of data, while a relative frequency distribution lists the ______ of occurrences of each category of data.
number, proportion
