According to a survey, 10% of Americans are afraid to fly. Suppose 1100 Americans are sampled. a) What is the probability that 121 or more americans in the survey are afraid to fly

The probability that 121 or more Americans in the survey are afraid to fly is 0.1335.

Step-by-step explanation:

Let X denote the number of Americans afraid to fly.

The proportion of Americans afraid to fly is, p = 0.10/

A random sample of n = 1100 Americans are selected.

The random variable X follows a Binomial distribution with parameters n = 1100 and p = 0.10.

But the sample selected is too large and the probability of success is close to 0.50.

So a Normal approximation to binomial can be applied to approximate the distribution of X if the following conditions are satisfied:

1.np ≥ 10

2.n(1 - p) ≥ 10

Check the conditions as follows:

Thus, a Normal approximation to binomial can be applied.

So,  

Compute the probability that 121 or more Americans in the survey are afraid to fly as follows:

Thus, the probability that 121 or more Americans in the survey are afraid to fly is 0.1335.

5

step-by-step explanation:

b: |12 – x| ≤ 0.25

step-by-step explanation:      

let x be the possible lengths in inches, of the ribbons jaime cut.

we have been given that jaime is cutting strips of ribbon for a project. he tries to cut each piece to be 12 inches long, but sometimes he cuts it too long or too short by as much as 0.25 inch.  

we can represent this information in an inequality as:

by the definition of absolute value function we will get,

upon combining our inequalities we will get,

therefore, the inequality   describes all the possible lengths (x), in inches, of the ribbons jaime cut.

step-by-step explanation: