Does LTE network performance vary between providers? The file LTE contains the download speed (in Mbps) on LTE connections of AT&T and Verizon providers in 31 U.S. large metro markets.

• At the 0.05 level of significance, is there evidence of a difference in the mean download speed between AT&T and Verizon?
• What assumption is necessary to perform this test?
• Construct and interpret a 95% confidence interval estimate of the difference in the mean download speed between AT&T and Verizon.

PLEASE SHOW WORK WITHOUT USING EXCEL

Region	AT&T (Mbps)	Verizon (Mbps)
Atlanta-Sandy Springs-Roswell	15.29	23.18
Austin-Round Rock	14.97	19.91
Baltimore-Columbia-Towson	16.12	16.33
Boston-Cambridge-Newton	14.97	16.26
Chicago-Naperville-Elgin	16.19	25.64
Cincinnati	12.79	14.24
Columbus	13.28	17.33
Dallas-Fort Worth-Arlington	12.96	17.05
Denver-Aurora-Lakewood	10.21	10.23
Detroit-Warren-Dearborn	14.21	23.64
Houston-The Woodlands-Sugar Land	13.06	13.54
Indianapolis-Carmel-Anderson	13.40	21.38
Kansas City	15.17	19.81
Los Angeles-Long Beach-Anaheim	13.62	20.03
Miami-Fort Lauderdale-West Palm Beach	10.67	24.52
Minneapolis-St. Paul-Bloomington	10.53	23.38
New York-Newark-Jersey City	12.54	17.37
Orlando-Kissimmee-Sanford	11.14	19.39
Philadelphia-Camden-Wilmington	15.22	12.92
Phoenix-Mesa-Scottsdale	11.16	15.45
Portland-Vancouver-Hillsboro	11.79	16.43
Riverside-San Bernardino-Ontario	14.63	21.68
Sacramento--Roseville--Arden-Arcade	15.41	21.72
San Antonio-New Braunfels	11.58	10.52
San Diego-Carlsbad	14.51	19.00
San Francisco-Oakland-Hayward	15.42	21.64
San Jose-Sunnyvale-Santa Clara	14.54	17.88
Seattle-Tacoma-Bellevue	13.52	17.85
St. Louis	13.22	20.12
Tampa-St. Petersburg-Clearwater	12.74	23.05
Washington-Arlington-Alexandria	14.87	13.67