Ch 9 Review - Different Regression Models

A chemist has a 100-gram sample of a radioactive material.  He records the amount of radioactive material every week for 6 weeks and obtains the following data: How much is left after 12 weeks?

• 15
• 21
• 17
• 19

Find the exponential model of the function.

• y = 100(8.8)^x
• y = 100(1.88)^x
• y = 100(.88)^x
• y = 100(.12)^x

Write the exponential regression equation for this data.

• Y = 8.16(2.7)^X
• Y = 81.6(2.7)^X
• Y = 8.16(.27)^X
• Y = 8.16(27)^X

Write the exponential regression equation for this data.

• Y = 8.16(2.7)^X
• Y = 81.6(2.7)^X
• Y = 8.16(.27)^X
• Y = 8.16(27)^X

Predict the year when Sugar Land’s population will reach 75,000.

• 2015
• 1991
• 1992
• 2010

After 9 days, approximately how many grams of this substance will exist?

• about 64244
• about 173602
• about 23774
• about 469111

Describe the association of the scatter plot

• Linear
• Linear; negative association
• Exponential; Growth
• Exponential; Decay

Use the exponential regression to find an equation that fits the​ data, where x is the years since 1990.

• y=8.92•1.23^x
• y=1.23•8.92^x
• y=8.92+1.23x
• y=8.92x+1.23

Please round your decimals to the nearest hundredth in your exponential regression!!!!!! What is the estimated number of cell phone subscribers in 2018?

• 2936 millions
• 847 millions
• 4441 millions
• 370 millions

In an exponential function, what does the 'a' represent? 

• SLOPE
• RATE OF CHANGE
• Y-INTERCEPT
• COMMON RATIO