Statistics and Probability Answers

(c) A random sample of size 30 is taken from Ρo (4) (i.e. Poisson distribution). Find
i. Ρ ( Χ < 4.5)
ii. Ρ ( Χ > 3.8)
iii. Ρ (3.8 < Χ < 4.5)

In a group of 78 people; 24 drink tea and 31 drink coffee. Find the probability that a person picked from this group at random is either tea or coffee drinker?
Find answer in fractions form.

A researcher reports that mice live an average of 40 months when their diets are sharply restricted and enriched with vitamins and proteins. Assume lifetimes of such mice are normally distributed with standard deviation 6.3 months.

1. Find the proportion of mice that live more than 55 months.

a patrol distributor records shows that sales average 3500 its per day with a stadard deviation 250 .. assume that the sales are normally distributed, find the probability of daily sales between 3300 litre 3800 litre?

From (12x,11)+(33x39)+(44x48)+(46x50)+(52x54)+(60x63)+(75x70), What is the mean of Y (

2.2 In a recent poll, 800 voters were randomly sampled and asked whether they would approve of
the building of an incinerator in the state. According to the poll, 450 voters approved and 350
voters disapproved. Is there enough evidence to argue that more than 50 % of the voters support
the building of the incinerator?
Use a 5 % level of significance
2.3 Suppose the Acme Drug Company develops a new drug, designed to prevent colds. The company
states that the drug is equally effective for men and women. To test this claim, they choose a
simple random sample of 100 women and 200 men from a population of 100,000 volunteers.
At the end of the study, 38% of the women caught a cold; and 51% of the men caught a cold.
Based on these findings, can we reject the company's claim that the drug is equally effective for
men and women? Use a 0.05 level of significance.

You are tasked with investigating whether fake news media platform and personality are independent. Consider the table below to help you with your task.

Celebrity .C/ Politician .P/ Sport Star .SS/ Total
Social Media .SM/ 1800 700 515 3015
Traditional Media .T M/ 485 350 150 985
Total 2285 1050 665 4000

Question 17
Which of the following statements is incorrect?
1. The expected frequency of Social Media and Politician is 791:44.
2. The expected frequency of Traditional Media and Sport Star is 163:76:
3. The observed frequency of Traditional Media and Politician is 350:
4. The null hypothesis is that Media platform and personality are dependent.
5. There are 2 degrees of freedom

An airline weekly flight data showed a 98% probability of being on time. If this airline has 15,000 flights in a year, how many flights would you predict to arrive on time?

Let X have a binomial distribution with n = 4 and P = 1/3 Find the probability. (i) P (X = 1) (ii) P (X = 3/2 ) (iii) P (X = 3) (iv) P (X = 6) (v) P (X ≤ 2) *