急！求救 #6 8 9 如果需要酬勞可私下談 （ex.$70題）
participation in informal
6.The National Science Foundation (NSF) sponsored a study on girls'
science, technology, engineering, or mathematics (STEM) programs. The results of the study were
published in Cascading Influences: Long-Term Impacts of Informal STEM Experiences for Girls
(March 2013). The researchers sampled 174 young women who recently participated in a STEM
program. They used a pie chart to describe the geographic location (urban, suburban, or rural) of
the STEM programs attended. Of the 174 participants, 107 were in urban areas, 57 in suburban
areas, and 10 in rural areas.
a.Determine the proportion of STEM participants from urban areas.
b.Determine the proportion of STEM participants from suburban areas.
c.Determine the proportion of STEM participants from rural areas.
d. Multiply each proportion in parts a-c by 360 to determine the pie slice size (in degrees) for each
e.Use the results, part d, to construct a pie chart for geographic location of STEM participants.
f.Interpret the pie slice for urban areas.
g.Convert the pie chart into a bar graph. Which, in your opinion, is more informative?
7. All high way bridges in the US are inspected periodically for structural deficiency by the FHWA.
Data from the FHWA inspections are compiled into the National Bridge Inventory (NBI). Classify
each variable below as quantitative or qualitative.
a. Length of maximum span (feet).
b. Number of vehicle lanes.
c. Toll bridge (yes or no).
d. Average daily traffic.
e. Condition of deck (good, fair, or poor).
f. Bypass or detour length (miles).
g. Route type (interstate, U.S., state, county, or city)
8. The NBI data were analyzed and the results made available at the FHWA Web site. Using the
FHWA inspection ratings, each of the 608,272 highway bridges in the US was categorized as
structural deficient, functionally obsolete, or safe. About 13.5% of the bridges were found to be
structural deficient, while 3.5% were functionally obsolete.
a. What is the variable of interest to the researchers?
b. Is the variable of part a quantitative or qualitative?
c. Is the data set analyzed a population or a sample? Explain.
d. How did the NBI obtain the data for the study?