Math Answers

A research firm conducted a study in 2014 and found that 40% of Internet users

received more than 10 emails per day. A similar study on the use of email

repeated in 2016.

i. Formulate the hypotheses that can be used to determine whether the

proportion of Internet users receiving more than 10 emails per day

increased in 2016.

i i. In a sample of 450 Internet users found 190 receiving more than 10 emails per

day, what is P-value?

iii. At a = 0.05, what is your conclusion?

(C) Consider the following hypothesis test:

Ho; = 10

H A : not equal to10

A sample of 50 provided a sample mean of 9.80. The population standard deviation is

4.

i. Compute the value of the test statistic.

i i. What is P-value?

iii. At a = 0.10, what is your conclusion?

Suppose that the continuous random variable x has the probability density function

f(x) = 1/2e−|x| , −∞ < x < ∞

find the m.g.f of x and use it to find E(x) and V ar(x).

Find the following probabilities if the random variable X is normally distributed with

mean 15 and standard deviation 3.

(i) P(X<10)

(ii) P(10<X<25 )

Given that Z is a standard normal random variable, find z for each situation,

(i) The area to the left of Z is 0.2115

(ii) The area to the right of Z is 0.5000

The average amount parents spent per child on private tuition classes is Rs 6000.

Assume that the standard deviation is Rs 1000 and that the amount spent is normally

distributed.

(i) Find the probability that the amount spent on a randomly selected child is:

a. Less than Rs 5000

b. Between Rs 5000 and Rs 6500

c. What is the probability that the amount spent on a randomly selected

child is between Rs 6500 and RS 8000. (06 marks)

(ii) Assume that 5% of parents spent over Rs 8000. If we selected randomly 1000

parents who sent their children to tuition, how many parents would spend more

than Rs 8000?

the score of shs students in their first quarter in statistic and probability brainly were analyzed and found to have a mean of 54.5and standard deviation of 7.5. find a 90% confidence interval

If scores are normally distributed with a mean of 30 and a standard deviation of 5.what percentage of the scores is?

If scores are normally distributed with a mean of 30 and a standard deviation of 5.what percentage of the scores is?

Assume that the average monthly earnings for the estate workers to be Rs 8500. A sample of 100 garment workers shows a sample mean is Rs 8000. Use a population standard deviation of Rs 1000.

(i) Formulate the null and alternative hypotheses that can be used to determine whether the sample data support the conclusion that the population mean wage is less than that of Rs 8500. (04 marks)

(ii) What is the value of test statistic?

(iii) What is the p-value?

(iv) What was the confidence interval?

(v) At a = 0.01, what is your conclusion. 

On average, four students visits the Mathematics and Statistics tutoring centre during a 5-minute period. (a) Calculate the probability that three students visit the centre during a 5- minute period. [3] (b) During a ten-minute period, what is the probability that at least 4 students visit the centre? [5] T

Three coins are tossed and the random variable Z gives the number of tails. Find

the range space, possible outcomes, and give the table of values.