Question

pretest: inferences and conclusions from data
8
select the correct answer.
what is the point estimate for the number of cars sold per week for a sample consisting of the following weeks: 1, 3, 5, 7, 10, 13, 14, 17, 18, 21?
a. 4.8
b. 5.22
c. 6.38
d. 6.1
(the left side has a table with week and cars sold columns, listing weeks 1 - 26 with corresponding cars sold numbers.)

Explanation:

Step1: Identify cars sold for each week

Week 1: 1, Week 3: 4, Week 5: 4, Week 7: 8, Week 10: 8, Week 13: 6, Week 14: 5, Week 17: 4, Week 18: 6, Week 21: 2.

Step2: Sum the values

Sum = \(1 + 4 + 4 + 8 + 8 + 6 + 5 + 4 + 6 + 2\) = \(48\).

Step3: Calculate the mean (point estimate)

Number of weeks (n) = 10. Mean = \(\frac{48}{10}\) = \(4.8\)? Wait, no, wait. Wait, let's re - check the values:

Wait, Week 1: 1, Week 3: 4, Week 5: 4, Week 7: 8, Week 10: 8, Week 13: 6, Week 14: 5, Week 17: 4, Week 18: 6, Week 21: 2.

Wait, 1+4 = 5; 5 + 4 = 9; 9+8 = 17; 17+8 = 25; 25+6 = 31; 31+5 = 36; 36+4 = 40; 40+6 = 46; 46+2 = 48. n = 10. 48/10 = 4.8? But wait, maybe I misread the table. Wait, let's check the table again.

Wait, Week 10: Cars Sold is 8? Wait the table:

Week 1:1, 2:1, 3:4, 4:2, 5:4, 6:10, 7:8, 8:5, 9:9, 10:8, 11:2, 12:5, 13:6, 14:5, 15:7, 16:1, 17:4, 18:6, 19:0, 20:9, 21:2, 22:5, 23:9, 24:5, 25:3, 26:3.

Ah! Wait, I think I made a mistake. Let's list the cars sold for the sample weeks:

Week 1: 1

Week 3: 4

Week 5: 4

Week 7: 8

Week 10: 8

Week 13: 6

Week 14: 5

Week 17: 4

Week 18: 6

Week 21: 2

Wait, that's 10 weeks. Let's sum again: 1 + 4 = 5; 5+4 = 9; 9 + 8 = 17; 17+8 = 25; 25+6 = 31; 31+5 = 36; 36+4 = 40; 40+6 = 46; 46+2 = 48. 48 divided by 10 is 4.8. But the option A is 4.8. But wait, maybe I missed a week? Wait the sample weeks are 1,3,5,7,10,13,14,17,18,21. That's 10 weeks. So the sum is 48, mean is 4.8. But wait, let's check again.

Wait Week 10: 8, Week 13:6, Week14:5, Week17:4, Week18:6, Week21:2.

Wait 1 (week1) +4 (week3)+4 (week5)+8 (week7)+8 (week10)+6 (week13)+5 (week14)+4 (week17)+6 (week18)+2 (week21) = 1+4=5; +4=9; +8=17; +8=25; +6=31; +5=36; +4=40; +6=46; +2=48. Yes, 48/10 = 4.8. So the point estimate (sample mean) is 4.8.

Answer:

A. 4.8