As Part of a Study of the Swimming Speed of Sharks

Multiple Choice

As part of a study of the swimming speed of sharks, a random sample of 18 lemon sharks (Triakis semifasciata) were observed in a laboratory sea tunnel. Body lengths and maximum sustainable swimming speeds ("MSSS," reported in body lengths per second) were measured for each shark. The computer output from a regression with y = MSSS and x = body length is given below. ​
Linear Fit MSSS=1.8928955-0.0104278 * Length
Summary of Fit
RSquare 0.526395
RSquare Adj 0.496794
S 0) 272031
Mean of Response 1.24
N Observations 18
​
Analysis of Variance
Source DF Sum of Squares Mean Square F Ratio
Model 1 1.3159870 1.31599 17.7834
Error 16 1.1840130 0.07400 Prob > F
Total 17 2.5000000 0.0007*
​
Parameter Estimates
Term Estimate Std Error t Ratio Prob > |t|
Intercept 1.8928955 0.167575 11.30 < 0.0001*
Length(cm) -0.010428 0.002473 -4.22 0.0007*
​
According to the above computer output, if body length increases by one unit, by how much will the swimming speed, in body lengths per second, change?
​

A) 1.893
B) -0.0104
C) -1.893
D) 1.184
E) -4.22