Answer:
Kindly check explanation
Step-by-step explanation:
To construct confidence interval for difference in proportion ; the following conditions must be met :
1.) The selected samples must have been randomly chosen or selected from a larger population. This is essential in other to eliminate bias.
Each group of samples must be independently chosen. That is, the samples of bug customers chosen must be independent of the sample of small customers selected.
The population from which the samples are drawn must be considerably larger than the sample size. Sample size, n should be ≤ 10% of the population size.
p1 = 160 / 200 = 0.8 ; (1 - p1) = 0.2
p2 = 120 / 300 = 0.4 ; (1 - p2) = 0.6
(p1 - p2) ± Zcritical * sqrt[(p1(1 - p1) /n1) + (p2(1 - p2) / n2)]
Answer:iidff
Step-by-step explanation:
rr
Answer:
m=3
Step-by-step explanation:
Complete Question
A set of magical wand prices are normally distributed with a mean of 50 dollars and a standard deviation of 4 dollars. A blackthorn wand has a price of 45.20. What proportion of wand prices are lower than the price of the blackthorn wand? You may round your answer to four decimal places
Answer:
0.1151
Step-by-step explanation:
We solve using z score formula
z = (x-μ)/σ, where
x is the raw score = $45.20
μ is the population mean = $50
σ is the population standard deviation = $4
We are solving for x < 45.20
Hence:
z = 45.20 - 50/4
z = -1.2
Probability value from Z-Table:
P(x<45.20) = 0.11507
Approximately to 4 decimal places = 0.1151
Therefore, the proportion of wand prices that are lower than the price of the blackthorn wand is 0.1151
