Answer:
The smallest sample size n that will guarantee at least a 90% chance of the sample mean income being within $500 of the population mean income is 48.
Step-by-step explanation:
The complete question is:
The mean salary of people living in a certain city is $37,500 with a standard deviation of $2,103. A sample of n people will be selected at random from those living in the city. Find the smallest sample size n that will guarantee at least a 90% chance of the sample mean income being within $500 of the population mean income. Round your answer up to the next largest whole number.
Solution:
The (1 - <em>α</em>)% confidence interval for population mean is:
The margin of error for this interval is:
The critical value of <em>z</em> for 90% confidence level is:
<em>z</em> = 1.645
Compute the required sample size as follows:
![n=[\frac{z_{\alpha/2}\cdot\sigma}{MOE}]^{2}\\\\=[\frac{1.645\times 2103}{500}]^{2}\\\\=47.8707620769\\\\\approx 48](https://tex.z-dn.net/?f=n%3D%5B%5Cfrac%7Bz_%7B%5Calpha%2F2%7D%5Ccdot%5Csigma%7D%7BMOE%7D%5D%5E%7B2%7D%5C%5C%5C%5C%3D%5B%5Cfrac%7B1.645%5Ctimes%202103%7D%7B500%7D%5D%5E%7B2%7D%5C%5C%5C%5C%3D47.8707620769%5C%5C%5C%5C%5Capprox%2048)
Thus, the smallest sample size n that will guarantee at least a 90% chance of the sample mean income being within $500 of the population mean income is 48.
Answer:
what number and what variable
Step-by-step explanation:
From the given data in the study of texting speed, we can identify the following
1)
a) population; is all the individuals belonging to the age group of 18-22 years
b) sample; is the selected 45 adults in the age group of 18-22 years
c) unit / individual: adults
d) Response: time taken to write "hi! what's up?"
2)
<h3>The response variable is </h3>
- A continuous - quantitative variable.
It is a continuous variable as it can take an infinite number of possible values.
<h3>The level of measurement is</h3>
- Measured by the ratio scale of measurement.
variables measured by the ratio scale of measurement have equal differences between scale values and equal quantitative meaning. They also have a true zero point
For more information on response variable, visit
brainly.com/question/14662435?referrer=searchResults
Answer:
4. 16.5 minutes 2508 words - Robert
5. 60 words (c)
6.I don't really know sorry :)
Step-by-step explanation:
4. 304 ÷ 2 = 1 minute 152 words - Robert
2508 ÷ 152 = 16.5 minutes 2508 words - Robert
5. 152 × 20 = 3040 words - Robert
483 ÷ 3 = 1 minute 161 words - Michaela
161 × 20 = 3220 words - Michaela
316 ÷ 2 = 1 minute 158 words - Laura
158 × 20 = 3160 words - Laura
= 3220 - 3160
= 60 words (c)
Please give me brainliest ;)
x^2+3x-18 in factored form leaves us the two factors of;
(x+6)(x-3)
So from your choices (x-3) is the answer
