Question

pln-2
If 10 coins are tossed 100 times, how many times would you expect 7 coins to fall head upward.
(a) 14
(b) 12
(c) 13
(d) 11​

Answer 1

Answer:

12 is the answer

Step-by-step explanation:

This is the binomial distribution (p+q)^10 with p =1/2, q = 1/2.

You can have 10 heads, probability of this is p^10 or 1/1024

9 heads 1 tail has pr = 10.p.q^9 = 10/1024

8 heads 2 tails has pr = 10C2.p^2.q^8 = 45/1024

7 heads 3 tails has pr = 10C3.p^7.q^3 = 120/1024

So in 100 trials of this you would expect 7 heads & 3 tails to occur 100 x 120/1024 times

or about 11.7 times. Nearly 12 times.

The nearest whole number is 12.

Answer 2

Answer:

the writ answer is 14 mean a is right answer