Headaches and Handedness

A study was conducted to investigate the relationship between severe headaches and being left or right handed¹. (Incidentally, Lisa Kudrow, who played Phoebe Buffay on the hit sitcom "Friends", is an author on this study.) Of273

participants with cluster headaches,24

were left-handed. Of477

participants with migraine headaches,42

were left-handed.

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Round your answers to three decimal places.

(a) Give an estimate for the proportion of cluster headache sufferers who are left handed.

p

^

=

(b) UseStatKeyor other technology to construct a95

%

confidence interval for the proportion of cluster headache sufferers who are left-handed.

The interval is

to

.

(c) Give an estimate for the proportion of migraine sufferers who are left-handed.

p

^

=

(d) UseStatKeyor other technology to construct a95

%

confidence interval for the proportion of migraine sufferers who are left-handed.

The interval is

to

.

(e) Compare your confidence intervals in parts (b) and (d). Which is more narrow?

The confidence interval from part (b)The confidence interval from part (d)

¹Messinger, H.B., Messinger, M.I., Kudrow, L., & Kudrow, L.V. "Handedness and headache."Cephalalgia, 1994; 14:64-67