The given values are:
p = 22% = 0.22
Zc = 1.645 at 90% confidence level.
margin of error, E = 0.04
The formula we can use here is:
E = sqrt(pq/n) * Zc
0.04 = sqrt(0.22*(1-0.22)/n)*1.645
n = (0.22*(1-0.22))*(1.645/0.04)^2
n = 290.22
hence minimum sample size = 290
Linear regression line y=2.1x+130 predicts sales based on the money spent on advertising.
Linear regression represents the relationship between two variables. the value of y depends on the value of x.
x represents the dollars spent in advertising and y represents the company sales in dollars.
We need to find out sales y when $150 spends on advertising.
Plug in 150 for x and find out y
y = 2.1 x + 130
y = 2.1 (150) + 130
y= 445
The company expects $445 in sales
Answer:
1,280
Step-by-step explanation:
Answer:
(25.53, 37.87): 95% CI
(23.59, 39.81): 99% CI
Step-by-step explanation:
The margin of error of a confidence interval is given by:
In which 
is the standard deviation of the population and n is the size of the sample.
z is related to the confidence level. The higher the confidence level, the higher the values of z, and thus, we wider the confidence interval is.
In this question:
The narrower C.I. is the 95%, and the wider is the 99%. So
(25.53, 37.87): 95% CI
(23.59, 39.81): 99% CI
Answer:
3.65
Step-by-step explanation:
