Many students face the problems when they start studying the Statistics and Probability subject. Trying to understand a lot of different aspects they feel stressed and that doesn’t have a beneficial effect on their health. Students have a great deal of **statistics and probability questions** that they puzzle over every day. Our service will provide every client with the statistics and probability answers. We promise to do our best to help you solve your **statistics and probability problems**, just let us know your problem and you will get the best statistics and probability answers ever!

### Ask Your question

### Search & Filtering

Suppose X1, X2 are iid exponential random variables with mean 2. If we invoke the Central Limit Theorem and assume that Xn-bar is normally distributed, how large must n be to insure that P[|Xn bar - 2| < .01] > .95?

I first standardized this and used Chebychev's inequality to get that (1/n) *( var/epsilon squared) < .05 so (1/n) *( 1/.005 squared) < .05 therfore n>800,000 . However this is the same answer I got when I did not invoke the CLT so I did something wrong somewhere. Can you please point out the mistake?

In Progress... |

normal-shaped distribution has μ = 80 and σ = 15.

a. sketch the distribution of sample means for samples of n = 25 scores from this

population

b. what are the z-score values that form the boundaries for the middle 95% of the distribution of the sample means?

c. compute the z-scores for M = 89 for a sample of n = 25 scores. Is this sample mean in the middle 95% of the distribution? Is this sample mean in the middle 99% of the distribution?

d. compute the z-score for M = 84 for a sample of n = 25 scores. Is this sample mean in the middle 95% of the distribution?

Answered! |

1. Compute each value requested for the following set of scores.

X

0 ΣX + 10

6 Σ(X + 10)

2 Σ(X + 1)2

3 Σ(X – 1)2 + 5

(X - X )2

2. For each of the following cases, name the observed variable and then classify (with expla- nation) the type and nature (discrete or continuous) of the scale:

a) Several respondents were interviewed and asked a few questions. For each question, their responses were coded as Strongly Agree, Strongly Disagree and No Comment.

b) A researcher is investigating the estimated time taken by students to complete an as- signment.

c) A poll studying the number of readers of three leading national news paper; Berita Ha- rian, Utusan Malaysia and New Straits Times.

d) A researcher is studying individual perception of his/her own self-esteem using a 10- point scale self-perception battery.

e) A teacher is grading her students’ academic performance into three different catego- ries: Low Achievers, Average Achievers and High Achievers

Answered! |

Three swimmers in 100m race, swimmer A is twice as likely to win as B and three times as to win as C. Find the probability that B or C wins. show us workings

Answered! |

Let is observed the height (cm) of the students in a school, and sample with size of 40 students is consider:

165,185,172,151,164,151,169,176,166,178,178,166,158,

165,151,172,184,174,158,172,164,151,169,176,166,178,

176, 158, 152,165,172,186,174,158,184,170,152,164,161,166.

After grouping the data into 6 class intervals with equal width:

a) Make a summary table for the grouped frequency, grouped relative frequency and “less than” grouped cumulative frequency distribution for the given data.

Answered! |

A company bought 20 000 shirts on the model Bitsiani. Quality control assurance of received goods is carried out using a random sample size of 400 shirts, in which were found 380 shirts without the defect. Find the confidence interval with confidence coefficient =0.90 for the probability:

If the selling price of a not defective shirt is 750 denars and defective shirt is sold with a 50% discount, find the range of the expected loss from receiving this delivery of goods.

In Progress... |

The restaurant Exclusive advertises delivery of ready prepared food. The announcement states that ordered food will be served for less than 50 minutes from receiving the order. Based on a random sample of 100 orders the average time for delivery of orders is calculated to be 49 minutes, and standard deviation of 5 minutes. What can be concluded on this random sample about the time of delivery with acceptable risk ?

Answered! |

Certain technological process is considered stable if the variance of a certain qualitative property is not greater than 2, otherwise the process is considered unstable. If from the sample with size 25 is obtained sample variance 1.8, what can you conclude about instability of the technological process with acceptable risk ?

In Progress... |

what scale of measurement is measuring statewide drug related crime rate (number of drug related arrests per 1000 individuals)

In Progress... |

Given a sample size of 65, with sample mean 726.2 and sample standard deviation 85.3, we perform the following hypothesis test.

Ho: μ = 750

H1: μ < 750

What is the conclusion of the test at the σ= 0.10 level? Explain your answer.

Answered! |