Question

Question 1 to 11, True or False? Applied business statistics

1) The width of the confidence interval depends only on the desired level of confidence 2) When population standard deviation is unknown, sample standaird deviation is used and the interval estimation is based on values from the t- rather than the z-distribution n 3) The z value for a 98% confidence interval around the point estimate is 2.33 4) In order to construct a 90% confidence interval for the population mean when the population standard deviation a is unknown and the sample of size n- 18, the appropriate t-value to use is 1 3304 5) When developing the interval estimates for the population proportion r, a z-distribution can be used ifn >5 and n (1-x)> 5 6) The formula to determine the sample size for the estimation of the popufation proportion to yield a desired error of estimation requires the value of , the population proportion When the value of r is unknown, researchers use a value of 0.25. )oome is on 1se bos 7) A null hypothesis must always include the equality signupanoo lcateng) 8) A hypothesis test always contains the possibility of committing one of two types of errors called Type I and Type Il errors dW( td Wa Mu uly ed 9) The null hypothesis is rejected if the p-value is greater than the significance level. 10) The probability of commiting a Type I error is called the level of significance pothesis based y In hypothesis testing the statistical conclusion is either to refeer or hol to reject the on the sample data. Gli-square goodness of fit testS are ehways ane-Lailed ests

Answer 1

Ans:

1)False,width of CI depends on confidence level,sample size and standard deviation.

2)False,t distribution is used only when n<30 and standard deviation is unknown.

3)True

4)False

df=18-1=17

t*=tinv(0.1,17)=1.740

5)True

6)False,as when p is unknown we consider p=0.5

7)False,it can have >= or <= signs

8)True

9)False,we reject Ho,when p-value<=alpha

10)True,P(type I error)=alpha

11)True,we reject H₀ or fail to reject H0,based on sample data.