nina1390

18.01.2021 • 

Mathematics

3. National Discount has 260 retail outlets throughout the United States. National evaluates each potential location for a new retail outlet in part on the mean annual income of the households in the marketing area of the new location. National develops an interval estimate of the mean annual income in a potential marketing area after taking a random sample of households.For a marketing area being studied, a sample of 36 households was taken and the sample mean income was $21,100.39. Based on past experience, National Discount assumes a known value of $4500 for σ=the population income standard deviation.a. Develop a 95% confidence interval for the mean annual income of households in this marketing area. (5 point)

Ответ:

ashleylit8

17.03.2022

Mathematics

---

(19630.39 , 22570.39)

Step-by-step explanation:

Given that:

Mean, m = 21100.39

Standard deviation, σ = 4500

Sample size, n = 36

Zcritical at 95% = 1.96

Confidence interval (C. I) :

m ± Zcritical(σ/√n)

21100.39± 1.96(4500/√36)

Lower bound :21100.39 - 1.96(750) = 19630.39

Upper bound : 21100.39+1.96(750) = 22570.39

(19630.39 , 22570.39)

---

0,0(0 оценок)

Ответ:

ssollers

08.09.2021

Mathematics

---

4 (4y - 7y^2) - 9(5y + 2) distribute through parenthesis
16y - 28y^2 - 45y + 18   combine like terms
 - 28y^2 - 16y - 45y + 18 simplify 
-28y^2 - 29y + 18, option C

hope this helps:D

---

0,0(0 оценок)