Skip to content

Course home

4.2 Statistical distributions (A-level only)

4.2 Statistical distributions (A-level only)

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233
Question 144

A botanist observes that the number of seeds, SSS, that germinate in a large nursery plot follows a binomial distribution S∼B(n,p)S \sim \text{B}(n, p)S∼B(n,p). The expected number of germinated seeds is 200.

a.

State the variance of SSS in terms of ppp.

[1]
b.

A normal distribution is used as an approximation for SSS. Using this approximation and a continuity correction, the probability that 180 or fewer seeds germinate is approximately 0.0384.

Show that 200−200p=11.02\sqrt{200 - 200p} = 11.02200−200p​=11.02 to 4 significant figures.

[5]
c.

Hence find the value of ppp, giving your answer to 2 significant figures.

[3]
Markscheme

4.2 Statistical distributions (A-level only) Questions

  1. A Level
  2. /Maths
  3. /4.2 Statistical distributions (A-level only)

328 exam-style questions on WJEC A Level Maths 4.2 Statistical distributions (A-level only), covering 4.2.1 Statistical distributions (A-level only), 4.2.2 Statistical distributions (A-level only), and 4.2.3 Statistical distributions (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

Question bank