Statistics and Probability Answers

In a group of 50 students, 40 students study Math, 32 study Physics and each student studies at least one of the subjects. Use this information to answer the questions below

2d) If a student is randomly selected, what is the probability that the student studies Math given that he or she DOES NOT study Physics?

The data shown represent the scores on a national achievement test for a group of tenth-grade students. Find the approximate scores that correspond to these percentiles.

score, frequency

196.5 - 217.5 [ 5

217.5 - 238.5 [ 17

238.5 - 259.5 [ 22

259.5 - 280.5 [ 48

280.5 - 301.5 [ 22

301.5 - 322.5 [ 6

a) 15th

b) 43th

The number of accidents in a highway as recorded every month over a 9 - month periods are 15,18,9,11,14,10,8,13,19. Test at 5% frequencies are in agreement with the belief that the number of accidents was the same during the 9 - months. it is given that the table values of x² at 5% level for 8 d.o.f and 9 d.o.f . are 15.5 and 16.9 respectively.

a laptop manufacturer claims that the latest model of laptop will last an average of 10 hours under normal use.A researcher randomly selects 25 laptops of the latest model form the company and tested these laptop have mean lifespan of 8.5 hours and standard deviation of 3,7 hours ,does the company have enough evidence that their claim is true at 1% level of significance

A die is thrown repeatedly until a 4 and a 5 was obtained. Find the expected number of throws required?

what is the probabilty that 0 doesnt appear among k digits chosen indepentantly and uniformy at random

In a normal distribution 31% of the items are under 45 and 8% are over 64 . Find the mean and standard deviation of the distribution

What measure of central value best estimates the population mean?

_______ is the procedure based on sample evidence and probability used to test statements regarding a characteristic of a population.

a. sampling

b. analyzing

c. hypothesis testing

d. collecting

The ______ is assumed to be true until we have evidence to the contrary.

A. null hypothesis

b. alternative hypothesis

c. level of significance

d. type I error