91Ó°ÊÓ

The number of left-handed pupils in the sample is denoted by the letter L.

The sample size is $100$.

In a large school, the percentage of left-handed kids is equal to $11$.

The following concept was used:

$10\%$condition

$\mathrm{n}<0.10\mathrm{N}$

According to the rule, if the sample represents less than 10% of the population, it is safe to assume that the trials are independent and may be modelled using the binomial distribution, regardless of the without replacement sample.

The sample size$\left(=100\right)$is less than ten percent of a large school's students.

Furthermore, the left-handedness of one student has no bearing on the left-handedness of another, therefore each student's trial is independent.

Since, $L~Bin(100,0.11)$

As a result, a binomial distribution can be used to model L.

The number of left-handed pupils in the sample is denoted by the letter L.

The sample size is $100$.

In a large school, the percentage of left-handed kids is equal to $11$.

Consider,

$$\begin{gathered} P(Lâ‰\yen 15)=1-P(L<15) \\ P(Lâ‰\yen 15)=1-P(L≤14) \end{gathered}$$

Using TI- 83 plus

a) Now Press on $2^{nd}$and then click on Dist.

b) Go to binomcdf with $↓$key.

c) Hit Enter

d) Type 100,0.11,14)

e) Hit Enter

The probability comes to be $0.86695$.

$$\begin{gathered} P(Lâ‰\yen 15)=1-0.86695 \\ P(Lâ‰\yen 15)=0.13305 \end{gathered}$$