Question

Case Study: Managing Ashland MultiComm Services [Basic Business Statistics, 14th Ed.) The AMS technical services dept. has embarked on a quality improvement effort. This project relates to maintaining the target upload speed for its Internet service subscribers The department wants to ensure that the mean target upload speed for all Internet service subscribers is at least 0.97 on a standard scale in which the target is 1.0. On a particular day, the upload speed was measured 50 times. The results are stored in AMS9 file from the Excel Data Workbooks ZIP file. 1. Use the data in AMS9 to calculate and report the summary statistics for this sample 2. Is there evidence that the population mean upload time is less than O.97? Conduct a hypothesis test making sure to report all the relevant metrics and your conclusion. 3. Given your conclusion, does AMS need to actively pursue altering their speeds given the results of your statistical analysis? O" Insert Page Layout Formulas Data Review View Home | Calibri (Body) -| | 11 А- Ar 秒· . | 1 EP wrap Text 물 | Merge & Center, Upload Speed 0.985 Median 0.959 Mean 0.024326 VAR 0.1559678 St DEV 1.219 50 Sample Size 0.977 0.621 MIN 1.044 1.286 MAX 0.778 10 1.122 1.114 12 1.091 13 1.086 14 15 1.141 16 0.723 17 18 1.060 19 1.047 0.800 0.889 1.012 24 0.734 P DATA + esc 088 Home Insert Page Layout Formulas Data Review View 5 Paste BIU 0.762 0.814 1.108 0.805 1.024 0.799 0.870 0.678 0.808 0.859 0.953 1.112 1003 DATA+ MacBook esc 2 Insert Page Layout Formulas ta ReviewView 姦| S Wrap Text FT Paste 2 011 23456789 10 1 2 3 4 5 6 7 8 9 20 21 22 23 24 25 26 27 0.854 0.985 Median 0.959 Mean 0.024326 VAR 0.155968 St DEV 50 Sample Size 0.621 MIN 1.286 MAX 0.778 1.122 0.934 1.060 0.800 0.889 0 695 0 993 MacBook Pro esc 名。

Answer 1

Answer:

1).

n=50, mean =0.959, sd=0.155968

2).

Single sample t test used

Ho : μ = 0.97 H1 : μ < 0.97

Lower tail test

(z-1)

0.959 0.97) t-- 0.1550075 50

= -0.4987              

Table value of t with 49 DF at 0.05 level =-1.6766

Rejection Region: Reject Ho if t < -1.6766

Calculated t = -0.4987 not in the rejection region

The null hypothesis is not rejected.

There is not enough evidence to support the claim that population mean upload time is less than 0.97.

3).

There is no need to actively pursue altering their speeds.

t Test for Hypothesis of the Mean
Data
Null Hypothesis                m=	0.97
Level of Significance	0.05
Sample Size	50
Sample Mean	0.959
Sample Standard Deviation	0.1559678
Intermediate Calculations
Standard Error of the Mean	0.0221
Degrees of Freedom	49
t Test Statistic	-0.4987
Lower-Tail Test
Lower Critical Value	-1.6766
p-Value	0.3101
Do not reject the null hypothesis