Statistics and Probability Answers

From the past experience, a prof knows that the test score of a student taking his final xm is a random variable with mean 75 and variance 25.what os can be said about the probability that a student will score between 65 and 85.

A sample random sample of size 4 is drown with replacement from a population with s.d. 6 what is the S. E of the sample mean?

You are the Manager of a new computer manufacturing company, Fongkomputer. Tests have shown that the mean life time of your computers is normally distributed, and on average your computers last for only 9 months, with a standard deviation of 3 months. The managing director wants the chance of computer being returned within its guarantee period to be 10%. Suggest a guarantee period that will achieve this objective. Round your solution to the nearest month

Using thye following information: H_0:=375; H_a: 375; n=100; x = 390; ²=4,900 and a =0.05. is the z-test statistic value equal to 2.14?

About how many % of scored distribution is between z=0 and z=1?

Find P(-1.2 <2<-0.2)

Show your solution using the critical value method.

a previous study on the effect of blended learning module on senior high school student's achievement revealed that mean score pi is 85 with standard deviation of 3. juliana, a senior high school statistic teacher, surveyed a class of 30 students test the hypothesis at a 0.10 level of significance

A group of the following students got the following score in a test:6,9,12,15,and 18.compute the mean of the sample mean

(a) state the null and alternative hypotheses, (b) compute the test

statistic, (c) determine the critical value and sketch the rejection region and non-rejection

region in the normal curve.

1. The cahier of a fast-food restaurant claims that the average amount spent by customers for dinner is

Php 120.00. A sample of 50 customers over a month was randomly selected and it was found out

that the average amount spent for dinner was Php 122.50. Construct the critical regions using a 0.05

level of significance to conclude that the average amount spent by customers is more than Php

120.00. Assume that the population standard deviation is Php6.50.

Given the following information, construct the rejection region. Show the solution in

a step-by-step procedure.

1. H 0 : = 84

H a : 84

m= 87, s= 10, n = 35, "\\alpha" = 0.05