Answer:
(0.25 ; 21.75)
8.7 (1 decimal place)
Step-by-step explanation:
Net change in scores : X = 6,14,12,23,0
Sample mean, xbar = (6 + 14 + 12 + 23 + 0) /5 = 55 /5 = 11
Sample standard deviation, s = 8.66 ( from calculator)
Sample standard deviation = 8.7( 1 decimal place)
Sample size, n = 5
The 95% confidence interval; we use t, because n is small
Tcritical at 95%, df = 4 - 1 = 3 ; Tcritical = 2.776
Xbar ± standard Error
Standard Error = Tcritical * s/√n
Standard Error = 2.776 * 8.66/√5
Standard Error = 10.751086 = 10.75
Lower boundary = (11 - 10.75) = 0.25
Upper boundary = (11 + 10.75) = 21.75
(0.25 ; 21.75)
The
