×
Get Full Access to Mathematics For The International Student: Mathematics Sl - 3 Edition - Chapter 20 - Problem 16
Get Full Access to Mathematics For The International Student: Mathematics Sl - 3 Edition - Chapter 20 - Problem 16

×

# Jana took seven spelling tests, each with ten words, but she could only find the results ISBN: 9781921972089 446

## Solution for problem 16 Chapter 20

Mathematics for the International Student: Mathematics SL | 3rd Edition

• Textbook Solutions
• 2901 Step-by-step solutions solved by professors and subject experts
• Get 24/7 help from StudySoup virtual teaching assistants Mathematics for the International Student: Mathematics SL | 3rd Edition

4 5 1 349 Reviews
13
1
Problem 16

Jana took seven spelling tests, each with ten words, but she could only find the results of five of them. These were 9, 5, 7, 9, and 10. She asked her teacher for the other two results and the teacher said that the mode of her scores was 9 and the mean was 8. Given that Jana remembers she only got one 10, find the two missing results.

Step-by-Step Solution:
Step 1 of 3

MAT 211­ Lecture 6­ 15.3 & 15.4 Section 15.3 Homework #8: ln(x,y)= x​ +y​2­y​x­2 lnx= 0 & lny= 0 1st Derivative:​ lnx= 2x­y​ lny= 2y­2yx I. 2x­y​=0 ­­­­­­­> x=1 2­y​=0 2=y​ y=­ 2 2​ 2y­2yx=0 ­­­­­­­> y=0 2x­y​ =0 2x­0=0 x=0 II. 2y(1­x)= 0 y=0 & x=1 Critical Points: (0,0); (1, ­ 2); (1, + 2) 2nd Derivative:​ lnxx= 2 lnxx (0,0)= 2 lnyy= 2­2x lnyy (0,0)= 2 lnxy= ­2y lnxy (0,0)= 0 H(0,0)= 2 * 2 ­ 0= 4 Since lnxx= 2>0, then we have a relative minimum at (0,0). ­Critical point at (1, ­ 2) : lnxx (1, ­ 2) =2 √ lnyy (1, ­ 2) =0 lnxy (1, ­ 2) =(­2)(­ 2) = 2 2 2 H (1, ­ 2)= 2 * 0 ­ (2 2)​ 0­8= ­8< 0 Since H is negative, we have a saddle point at (1, ­ 2). ­Critical point at (1, + 2) : lnxx (1, + 2)=2 lnyy (1, + 2)=0 lnxy (1, + 2)= ­2( 2) 2​ H(1, + 2) = 2* 0­ (­2 2)​= 0­8= ­8<0 Since H is negative, we have a saddle point at (1, + 2). Homework #11: M(c,f)= 11+8c+4c​ 2­40f­20cf+40f​2 Mc= 8+8c­20f­­­­­­­> 8+8c­20f= 0 divide by 4 2+2c­5f=0 Mf= ­40­20c+80f­­­­> ­40­20c+80f=0 divide by 20 ­2­c+4f=0

Step 2 of 3

Step 3 of 3

## Discover and learn what students are asking

Chemistry: The Central Science : Molecular Geometry and Bonding Theories
?Give approximate values for the indicated bond angles in the following molecules:

Statistics: Informed Decisions Using Data : Estimating a Population Standard Deviation
?5. 90% confidence, n = 20

Statistics: Informed Decisions Using Data : Comparing Three or More Means (One-Way Analysis of Variance)
?In Problems 9 and 10, determine the F-test statistic based on the given summary statistics. [Hint: x =?nixi / ?ni.]

Statistics: Informed Decisions Using Data : Testing the Significance of the Least-Squares Regression Model
?In Problems 5–10, use the results of Problems 7–12, respectively, from Section 4.2 to answer the following questions: (a) What are the estima

Statistics: Informed Decisions Using Data : Inference about the Difference between Two Medians: Dependent Samples
?Effects of Exercise To determine the effectiveness of an exercise regimen, a physical therapist randomly selects 10 women to participate in a study. S

Unlock Textbook Solution