Question

mal 3-27 nia l- 8-6-4 -2 0 2 468 10 12 FIGURE 3.15 A Normal curve, for Exercises 3.17 and 3.18. 3.19 The distribution of hours of sleep per week 3.2 among college students, is found to be Normall tributed, with a mean of 6.5 hours and a standard d ation of 1 hour. What range contains the middle 9s of hours slept per week night by college students? (a) 5.5 and 7.5 hours per week night y & des, 95% (b) 4.5 and 7.5 hours per week night (c) 4.5 and 8.5 hours per week night

Answer 1

Solution:

Given in the question

Mean = 6.5

Standard deviation = 1

From the empirical formula we found that z =+/-2 which contains 95% values

So x bar

2 = (Xbar- 6.5)/1

Xbar = 8.5

For lower limit

-2 =( Xbar-6.5)/1

Xbar = 4.5

So 4.5 to 8.5 hours per night contains the middle 95% of hours slept per week night by college students.