43 Chapter i 62 lectur x ssa Pinecrest Avenue SE, Eat x Sign in to your account

Question

43 Chapter i 62 lectur x ssa Pinecrest Avenue SE, Eat x Sign in to your account x LON-CAPA Driving Expenses c Secure https://s1.ite msu. mth106hwD9-SS1-Driving costs problem?symb uploaded 62 msu%21BA69421501f 46816msu1%2tdefaut 10654 o According to AAA last year the average American spent $7,000 in driving expenses. Let's assume that driving expenses follow a normal distrbution with standard deviation of ss00. Use the graph of the normal distribution to help answer the following questions. a. What percentage of American drivers spend less than $7.000 per year? b. What percentage spend between $6,500 and s7,000 subme Answer Tries 08 What percentage spend less than $6,500 submit Answer Tries OVB d. What percentage spend between $6,500 and s8,000 surer Anwer Tries 0/8 e. What percentage spend more than $8,500? Tries 0/8 What percentage spend more than $7.250 Tries 0/8 g. What percentage spend between s6,50o and s7.250

Explanation / Answer

let X denotes the driving expenses

so X~N(7000,5002). so Z=(X-7000)/500~N(0,1)

a) P[X<7000]=P[(X-7000)/500<(7000-7000)/500]=P[Z<0]=0.5=50%

50% of the american drivers spend less than $7000 [answer]

b) P[6500<X<7000]=P[(6500-7000)/500<(X-7000)/500<(7000-7000)/500]=P[-1<Z<0]=P[Z<0]-P[Z<-1]=0.5-0.1586553=0.3413447

34.13447% of the american spend between $6500 and $7000 [answer]

c) P[X<6500]=P[(X-7000)/500<(6500-7000)/500]=P[Z<-1]=0.1586553

15.86553% of the americans spend less than $6500 [answer]

d) P[6500<X<8000]=P[(6500-7000)/500<(X-7000)/500<(8000-7000)/500]=P[-1<Z<2]=P[Z<2]-P[Z<-1]

=0.9772499-0.1586553=0.8185946

81.85946% of the americans spend within $6500 and $8000 [answer]

Related Questions

Navigate

• Browse (All)
• Browse 4
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.