If you ask 100 people and 60 say they are students, then you would assume that 60/100 people in town as a whole are students. To estimate the non-student population, you would infer that the other 40 are not students, thus making the non-student to student ratio 40:60 or 2:3 when simplified. This means that for every 2 non-students, there are 3 students. If we multiply 2000 by this 2:3 ratio, we would see that 2/3*2000 = the non-student population.The non-student population is estimated at 1,333.

4 0

3 years ago

A textbook company states that the average time a student needs to take a quiz from its book is 30 minutes with a standard devia

faltersainse [42]

Answer:

We conclude that her students, on average, do not take 30 minutes on the quiz, contrary to what the textbook company states.

Step-by-step explanation:

We are given;

Population mean; μ = 30 minutes

Population standard deviation; σ = 3 minutes

Sample size; n = 10

Sample mean; x¯ = 25

Significance level = 5% = 0.05

Let's define the hypotheses;

Null hypothesis; H0: μ = 30

Alternative hypothesis: Ha: μ ≠ 30

Let's find the test statistic;

z = (x¯ - μ)/(σ/√n)

z = (25 - 30)/(3/√10)

z = -5.27

From online p-value from z-score calculator attached using, z = -5.27, significance level = 0.05, two tailed hypothesis, we have;

p < 0.00001

This is less than the significance level, and so we will reject the null hypothesis and conclude that Her students, on average, do not take 30 minutes on the quiz, contrary to what the textbook company stated.

8 0

2 years ago

Read 2 more answers