Question

A coin is tossed 11 times. What is the probability of obtaining exactly 9 heads?
A. 0.0269
B. 0.0054
C. 0.1611
D. 0.0806

Answer 1

\[\Large P=\left(\begin{array}{c}11\\9\end{array}\right)\times\left(\frac12\right)^{11}\]

Answer 2

0.0054 (B)

Answer 3

This is not what I have calculated

Answer 4

Before i got A(0.0269), could that be correct?

Answer 5

11C9 = 55
½^11 is 1/2048

Answer 6

?

Answer 7

Yep I got A

Answer 8

thank you!

Answer 9

no problem