Question 1197871: 750 eggs are randomly sampled from a population where 14% of all eggs are fertilized. Use the normal approximation to the binomial to find the following probabilities rounded to 3 decimal places.
a. Find the probability that exactly 106 of the eggs are fertilized. Correct
b. Find the probability that at least 106 of the eggs are fertilized. Incorrect
c. Find the probability that fewer than 106 of the eggs are fertilized. Incorrect
d. Find the probability that between 104 and 106, inclusive, of the eggs are fertilized.
Found 2 solutions by ewatrrr, ikleyn: Answer by ewatrrr(24785) (Show Source):
You can put this solution on YOUR website! Binomial Distribution:
n = 750, p = .14
Using the normal approximation and the NOted continuity correction factor.
(the continuity correction factor used as a Binomial Distribution is not continuous)
mean = 750*.14 = 105
sd = = 9.50
Using TI or similarly an inexpensive calculator like an Casio fx-115 ES plus
P(x = 106) = normcdf( 105.5,106.5, 105,9.5) = .0417
P(x ≥ 106) = normcdf( 105.5, 9999, 105, 9.5)= .4790
P(x < 106) = normcdf(-9999, 105.5, 105, 9.5)= .5210
P( 104 ≤ x ≤ 106) = = normcdf( 103.5,106.5, 105,9.5) = .1255
Answer by ikleyn(52776) (Show Source):
You can put this solution on YOUR website! .
750 eggs are randomly sampled from a population where 14% of all eggs are fertilized.
Use the normal approximation to the binomial to find the following probabilities rounded to 3 decimal places.
a. Find the probability that exactly 106 of the eggs are fertilized. Correct
b. Find the probability that at least 106 of the eggs are fertilized. Incorrect
c. Find the probability that fewer than 106 of the eggs are fertilized. Incorrect
d. Find the probability that between 104 and 106, inclusive, of the eggs are fertilized.
~~~~~~~~~~~~~~~~~~~~~~
You have a binomial distribution with large number of trials n = 750 and
individual probability of success p = 0.14.
You want to approximate it by the normal distribution.
You should use the mean value m = p*n = 0.14*750 = 105 and standard deviation
SD = = = 9.5026.
Also, you should use the continuity correction factor.
About approximation of the binomial distribution by normal distribution and continuity correction factor
see your textbook and/or these Internet sources
https://www.statisticshowto.com/probability-and-statistics/binomial-theorem/normal-approximation-to-the-binomial/
https://online.stat.psu.edu/stat414/lesson/28/28.1
https://stats.libretexts.org/Courses/Las_Positas_College/Math_40%3A_Statistics_and_Probability/06%3A_Continuous_Random_Variables_and_the_Normal_Distribution/6.04%3A_Normal_Approximation_to_the_Binomial_Distribution
For calculations, you may use your calculator (function normcdf), or Excel spreadsheet (function NORMDIST);
or online calculator https://onlinestatbook.com/2/calculators/normal_dist.html
(a) In this case, you should calculate the area under the normal curve between 105.5 and 106.5
(using the correction factor)
P(x = 106) = normcdf(105.5, 106.5, 105, 9.5026)= 0.0417 (rounded)
(b) In this case, you should calculate the area under the normal curve on the right from 105.5
(using the correction factor)
P(x >= 106) = normcdf(105.5, 9999, 105, 9.5026) = 0.479 (rounded).
(c) In this case, you should calculate the area under the normal curve on the left from 105.5
(using the correction factor)
P(x < 106) = normcdf(-9999, 105.5, 105, 9.5026) = 0.521 (rounded).
Notice that it is the complement to the value of probability in (b)
(d) In this case, you should calculate the area under the normal curve between 103.5 and 106.5
(using the correction factor)
P(104 <= x <= 106) = normcdf(103.5, 106.5, 105, 9.5026) = 0.125 (rounded).
Solved.
---------------
If you are a beginner student in learning probability distribution, I advise you to start learning
this kind of computations using the online calculator, to which I referred above.
It provides a graphical support, so at each step you do understand what you are doing.
In addition, this graphical support prevents you from making mistakes.
When you learm enough this kind of computations, you can switch to your regular calculator,
but even then you may use the online calculator for checking purposes.
|
|
|