Statistics and Probability Answers

‘Bhartdarshan’ is an Internet-based travel agency wherein customers can see videos of the cities they plan to visit. The number of hits daily is a normally distributed random variable with a mean of 10,000 and a standard deviation of 2,400.

a. What is the probability of getting more than 12,000 hits?

b. What is the probability of getting fewer than 9,000 hits?  

1. The teacher would like to find out if there is significant difference in the performance of the male and female students in 35 item test in English. He wants to consider 0.005 level of significance. The result is shown below:

MALE STUDENTS

sample size = 8

sample mean = 24.27

standard deviation = 9.36

FEMALE STUDENTS

sample size = 7

sample mean = 21.07

standard deviation = 8.25

A random sample of 25 brand A cigarettes showed an average nicotine content of 5 milligrams, while a sample of 40 brand D cigarettes showed average nicotine of 4.8 milligrams. If the standard deviation of nicotine is 1.6 milligrams, would you say that brand D has a lesser nicotine content? Use a 0.01 level of significance. Assume the distribution of nicotine content to be normal

Engineers in charge of maintaining out nuclear fleet continually check for corrosion inside the pipes that are part of cooling system. The inside condition of the popes cannot be observed directly but a non-destructive test can give an indication of possible corrosion. The test is not infallible. The test has probability of 0.7 of detecting corrosion when it is present but it also has probability of 0.2 of falsely indicating internal corrosion. Suppose the probability that any section of pipe has internal corrosion is 0.1.

The weights (in kg) of Grade 11 ICT follow a normal distribution and has a mean of 52 and standard deviation of 6. How many students have weights greater than 55?

A small-time bingo card costs P100.00 for 5 games. The prize for the first three games is P5,000.00, the fourth is P10,000.00 and the last prize is P20,000.00. If 1,000 bingo cards are going to be sold and you could only win once, what is the expected value of a ticket? With explanation.

The average height of students in a freshman class of a certain school has been 168.67 cm with a population standard deviation of 8.67 cm. Is there a reason to believe that there has been a change in the average height if a random sample of 49 students in the present freshman class has an average height of 155.04 cm? Use a 0.1 level of significance.

What are the given? Write only the number. :

population mean:Blank 1 cm

population standard deviation:Blank 2 cm

sample size:Blank 3

sample mean:Blank 4 cm

level of significance:Blank 5

What are the critical values? Write the positive critical value first then the negative.

z:Blank 6 andBlank 7

What is the value of the calculated z? Round your answer to the nearest hundredths.

z:Blank 8

null hypothesis a nutrionist claims that the average amount of vitamin b in a bread is more than 5grams

In a random sample of 300 patients, 21 experienced nausea. A drug manufacturer claims that fewer than 10% of patients who take its new drug for treating Alzheimer’s disease will experience nausea. Test this claim at the 0.05 significance level. What is the appropriate null hypothesis for this situation