Ask Question, Ask an Expert


Ask Statistics and Probability Expert

Hypothesis testing for single population mean.

State College is evaluating a new English composition course for freshmen. A random sample of n = 25 freshmen is obtained and students are placed in course throughout their first semester. One year later, a writing sample is obtained for each student and writing samples are graded using a standardized evaluation technique. The average score for the sample is M = 76. For the general population of college students, writing scores form a normal distribution with mean of m = 70.

a. If the writing scores for the population have the standard deviation of s = 20, does the sample provide enough evidence to conclude that the new composition course has a significant effect? Assume a two-tailed test with a = 0.05.
b. If the population standard deviation is s = 10, is the sample sufficient to show a significant effect? Again, assume a two-tailed test with a = 0.05.
c. in brief describe why you reached different conclusions for part (a) and part (b).

Statistics and Probability, Statistics

  • Category:- Statistics and Probability
  • Reference No.:- M922747

Have any Question? 

Related Questions in Statistics and Probability

Letnbspnbspbe a sequence of iid random variables with

Let   be a sequence of IID random variables with finite mean, µ, and let S n  be the sequence of sample means, (a) Show that the characteristic function of S n  can be written as  (b) Use Taylor's theorem to write the ch ...

Mimi made a random guess at 10 true-or-false questions let

Mimi made a random guess at 10 true-or-false questions. Let event A be she got at least 6 correct answers. What is the complement of event A? Please explain your answer.

Let x and ynbsp be zero-mean jointly gaussian random

Let X and Y  be zero-mean jointly Gaussian random variables with a correlation coefficient of and unequal variances of  (a) Find the joint characteristic function,  (b) Using the joint characteristic function, find the c ...

Letnbspnbspbe the psd function of a wss discrete-time

Let   be the PSD function of a WSS discrete-time process    Recall that one way to obtain this PSD function is to compute   and then take the DFT of the resulting autocorrelation function. Determine how to find the avera ...

Suppose x is a gamma random variable with

Suppose X is a Gamma random variable with PDF,      Find the Chernoff bound for the tail probability,

Consider a t distribution with 22 degrees of freedom

Consider a t distribution with 22 degrees of freedom. Compute p(t Consider a t distribution with 17 degrees of freedom. Find the value of c such that P(-C

A stationary random process xt has a mean of mux and

A stationary random process, X(t), has a mean of μ X and correlation function, .  A new process is formed according to Y(t) = aX(t) + b or constants a  and Find the correlation function

Suppose a zero-mean gaussian random processxt has a psd

Suppose a zero-mean Gaussian random process,X(t) , has a PSD given by  We desire to simulate a 5-ms segment of this process sampled at a rate of 2 kHz. Therefore, 10 samples will need to be created in our simulation. We ...

Questionhypothesis testing for two populationscaption labor

Question: Hypothesis Testing for Two Populations Caption : Labor negotiations have reared their ugly head again! TNH Industry Human Resources department is concerned about the perception of the hours worked per week at t ...

Find the psd of the processexercise let wnnbspbe an iid

Find the PSD of the process. Exercise Let W n  be an IID sequence of zero-mean Gaussian random variables with variance    Define a discrete-time random process   where   is a constant. (a) Find the mean function  (b) Fin ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

A cola-dispensing machine is set to dispense 9 ounces of

A cola-dispensing machine is set to dispense 9 ounces of cola per cup, with a standard deviation of 1.0 ounce. The manuf

What is marketingbullwhat is marketing think back to your

What is Marketing? • "What is marketing"? Think back to your impressions before you started this class versus how you

Question -your client david smith runs a small it

QUESTION - Your client, David Smith runs a small IT consulting business specialising in computer software and techno

Inspection of a random sample of 22 aircraft showed that 15

Inspection of a random sample of 22 aircraft showed that 15 needed repairs to fix a wiring problem that might compromise

Effective hrmquestionhow can an effective hrm system help

Effective HRM Question How can an effective HRM system help facilitate the achievement of an organization's strate