Answer:
9/5
Explanation:
original fraction : x/y
new fraction = .9x/(.5y)
= 9x/5y
(9x/5y) / (x/y)
= 9x/5y * y/x
= 9/5
= 1.8
so it increased by 80%
e.g suppose we had 100/200 or 1/2
new fraction = 90/100 or 9/10
new ratio = (9/10) / (1/2)
= 9/5
C- correct a mistaken view
The author is correcting the idea that Harriet Ida Pickens and Frances Wills were the first African American women to serve in the navy.
The ability to generalize a study's results to different circumstances is known as external validity that suffers from 7 types of threats.
<h3>What are the threats to External Validity?</h3>
There are 7 major threats to external validity.
- The first threat is sampling bias, in which a sample is not representative of the population.
- The second threat is history, where an unrelated incident can affect the results.
- The third threat is observer bias, in which the traits or actions of the experimenter unintentionally affect the results, resulting in bias and other demand features.
- The fourth threat is the Hawthorne effect, which describes the propensity for individuals to alter their behaviour merely because they are aware that they are being observed.
- The fifth threat is the Testing Effect, in which the results are impacted by whether a test is administered before or after another.
- The sixth threat is the aptitude-treatment, which involves the interaction of individual and group factors to affect the dependent variable.
- The environment, time of day, location, researcher traits, and other variables that restrict the generalizability of the results are included in the seventh threat.
To learn more about external validity, refer:
brainly.com/question/28760166
#SPJ4
The american would think of having children
