Using the normal approximation to the binomial, it is found that there is a 0.0107 = 1.07% probability that more than 30 are single.
<h3>Normal Probability Distribution</h3>
The z-score of a measure X of a normally distributed variable with mean 
and standard deviation 
is given by:
- The z-score measures how many standard deviations the measure is above or below the mean.
- Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.
- The binomial distribution is the probability of x successes on n trials, with p probability of a success on each trial. It can be approximated to the normal distribution with
.
In this problem, the proportion and the sample size are, respectively, p = 0.22 and n = 200, hence:
The probability that more than 30 are single, using continuity correction, is P(X > 30.5), which is <u>1 subtracted by the p-value of Z when X = 30.5</u>, hence:
Z = -2.3
Z = -2.3 has a p-value of 0.0107.
0.0107 = 1.07% probability that more than 30 are single.
More can be learned about the normal distribution at brainly.com/question/24663213
According to the research, Dr. Smithe should use naturalistic observation to investigate aggressive preschoolers.
<h3>What are naturalistic observations?</h3>
It is a method used in research and whose basis is to observe the subjects in the place where they live, without the researcher being disturbed in the least.
This allows detailing the behavior of the subjects that we record is what, in fact, the behavior that should happen in their habitat, under those conditions, obtaining real results, without any type of alteration.
Therefore, we can conclude that according to the research, Dr. Smithe should use naturalistic observation to investigate aggressive preschoolers.
Learn more about naturalistic observation here: brainly.com/question/8187021
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Answer:
Answer:
Stabilizer with area = 14 cm².
Step-by-step explanation:
Area of the wing = 101.25 cm²
Rule of the thumb is that area of stabilizer must be about 1/6 to 1/8 of the area of wing. So, first we calculate 1/6 of the area of the wing and 1/8 of the area of the wing. Area of stabilizer must be in between these two numbers.
1/6 of the area of wing = \frac{1}{6} \times 101.25 = 16.87561×101.25=16.875
1/8 of the area of wing = \frac{1}{8} \times 101.25 = 12.65681×101.25=12.656
This means, the area of horizontal stabilizer must be in between 12.656 cm² and 16.875 cm². From the given options only one option lies in between these two numbers and that is 14 cm²
Therefore, area of a good stabilizer design from the given options would be 14 cm²
The statement that is FALSE among the given options on hypothesis testing is;
Option D; Reducing the significance level (α) can increase a test's effectiveness.
This is about hypothesis testing.
Let us look at each of the options.
- A) When we increase the sample size, it means the testing becomes more sensitive and as such we are more likely to reject the null hypothesis. Thus, it increases the effectiveness.
- B) Alpha (α) is defined as the probability of rejecting the null hypothesis. Thus it is the probability of making a Type I error.
- C) Expanding the sample size makes the hypothesis test to be more sensitive. That is makes it more likely to reject the null hypothesis when it is false and as such it increases the power of the test.
- D) The lower the significance level, the lower the power of the test and as such the lesser the tests effectiveness.
Read more about hypothesis testing at; brainly.com/question/15980493
