Respuesta :
Answer:
5th percentile = 160.852 days
3rd quartile = 220.22 days
Step-by-step explanation:
Let X be the random variable representing the waiting time.
Here the mean(\mu) = 203 days
Standard deviation (\sigma) = 25.7 days
For calculating the 5th percentile, we need to find the z- score having area 0.05.
By Z-score table we have Z= -1.64
Now, Using formula X=Z\sigma +\mu
X = (-1.64)*(25.7)+203
= 160.852 days
Waiting time representing 5th percentile = 160.852 days.
For calculating third quartile, we know that third quartile represents the area to the left of 75% = 0.75
Hence, we need to calculate the Z score when the area is 0.75. Using the table we get Z= 0.67
X = (0.67)*(25.7)+203
= 220.22 (days)
Waiting time representing third quartile = 220.22 days
The waiting time represents the [tex]5th[/tex] percentile is [tex]\boxed{160.73{\text{ }}\,{\text{days}}}[/tex].
The waiting time represents the [tex]3rd[/tex] quartile is [tex]\boxed{220.22{\text{ }}\,{\text{days}}}[/tex].
Further Explanation:
The Z score of the standard normal distribution can be obtained as,
[tex]{\text{Z}} = \dfrac{{X - \mu }}{\sigma }[/tex]
Given:
The mean of test is [tex]\boxed{203}[/tex].
The standard deviation of the waiting time is [tex]\boxed{25.7}[/tex].
Explanation:
The value of z-score with fifth percentile can be obtained from the table is [tex]1.6449[/tex].
The z-score is [tex]1.6449[/tex].
The waiting time represents the [tex]5th[/tex] percentile can be obtained as,
[tex]\begin{aligned} \left( { - 1.6449} \right) &= \frac{{{\text{X}} - 203}}{{25.7}} \hfill \\ \left( { - 1.6449} \right) \times \left( {25.7} \right) &= {\text{X}} - 203 \hfill \\ - 42.27 &= {\text{X}} - 203 \hfill \\ - 42.27 + 203 &= {\text{X}} \hfill \\ {\text{160}}{\text{.73}&= X}} \hfill \\ \end{aligned}[/tex]
The waiting time represents the [tex]5th[/tex] percentile is [tex]\boxed{160.73{\text{ }}\,{\text{days}}}[/tex].
The value of z-score with third quartile can be obtained from the table is [tex]0.67[/tex].
The z-score is [tex]0.67[/tex].
The waiting time represents the 3rd quartile can be obtained as,
[tex]\begin{aligned} 0.67 &= \frac{{{\text{X}} - 203}}{{25.7}} \hfill \\ 0.67 \times \left( {25.7} \right) &= {\text{X}} - 203 \hfill \\ 17.19 + 203 &= {\text{X}} \hfill \\ {\text{220}}{\text{.22}} &= {\text{X}} \hfill \\ \end{aligned}[/tex]
The waiting time represents the [tex]3rd[/tex] quartile is [tex]\boxed{220.22{\text{ }}\,{\text{days}}}[/tex].
Learn more:
1. Learn more about normal distribution https://brainly.com/question/12698949
2. Learn more about standard normal distribution https://brainly.com/question/13006989
3. Learn more about confidence interval of mean https://brainly.com/question/12986589
Answer details:
Grade: College
Subject: Statistics
Chapter: Confidence Interval
Keywords: Z-score, Z-value, binomial distribution, standard normal distribution, standard deviation, criminologist, test, measure, probability, low score, mean, repeating, indicated, normal distribution, percentile, percentage, undesirable behavior, proportion, empirical rule.