Based on a random sample of 1140 adults, the mean amount of sleep per night is 7.96 hours. Assuming the population standard deviation for the amount of sleep per night is 1.6 hours, construct 95% confidence interval for the mean amount of sleep per night. a. (7.67, 8.05)
b. (7.87, 8.05)
c. (8.09, 9.12)
d. (7.87, 8.23)

at 95% confidence interval,  the mean amount of sleep per night is ( 7.87, 8.05 ).

Option b) (7.87, 8.05) is the correct answer.

Step-by-step explanation:

Given the data in the question;

sample size n = 1140

sample mean x" = 7.96

standard deviation σ = 1.6

At 95% confidence interval,

significance level ∝ = 1 - 95% = 1 - 0.95 = 0.05

∝/2 = 0.05 / 2 = 0.025

Z-Critical = = 1.96

Top get the Margin of error E;

E = × ( σ /√n )

we substitute

E = 1.96 × ( 1.6 /√1140 )

E = 0.09

So, At 95% confidence interval of the population mean is;

⇒ x" ± E

⇒ x" - E or x" + E

we substitute

⇒ 7.96 - 0.09, 7.96 + 0.09

⇒ 7.87, 8.05

Therefore, at 95% confidence interval,  the mean amount of sleep per night is ( 7.87, 8.05 ).

Option b) (7.87, 8.05) is the correct answer.

y < -3

step-by-step explanation:

-3y - 2 > 7

-3y -2 + 2 > 7+2

-3y > 9

-3y/-3 < 9/-3   (change the inequality sign when multiplying or dividing by a negative number)

y < -3

the highest percentage for deaths in construction from highest to lowest is as follows: falls, struck by objects, electrocution, and caught-in/between. these four are collectively known as fatal four.

in the case of falls, the type that is responsible for the overall highest death in the category is falls from roofs.