Biologists studying the healing of skin wounds measured the rateat which new cel
ID: 2955221 • Letter: B
Question
Biologists studying the healing of skin wounds measured the rateat which new cells closed a razor cut made in the skin of ananesthetized newt. The measurement was the amount of scartissue that developed per hour (in micrometers). Based on thedata below, complete the table.
29
27
34
40
22
28
14
35
26
35
12
30
23
18
11
22
23
33
90% CI
[ , ]
95% CI
[ , ]
99% CI
[ , ]
29
27
34
40
22
28
14
35
26
35
12
30
23
18
11
22
23
33
Explanation / Answer
Given n=18, xbar=25.67, s=8.32 (based on the data) (1) For 90% CI, =0.1, |t(0.05,df=n-1=17)|= 1.74 (checkstudent t table) So the 90% CI is xbar ± t*s/n --> 25.67 ± 1.74*8.32/sqrt(18) --> (22.26, 29.08)