![lberries08](/avatars/38337.jpg)
lberries08
01.11.2019 •
Mathematics
The grades on a statistics test are normally distributed with a mean of 62 and q1=52. if the instructor wishes to assign b's or higher to the top 30% of the students in the class, what grade is required to get a b or higher? round your answer to two decimal places.
Solved
Show answers
More tips
- A Animals and plants What Do Terriers Eat?...
- F Food and Cooking Discover the Benefits and Properties of Dates...
- C Computers and Internet Dynamically Assigned IP Address: What Is It and How Does It Work?...
- S Style and Beauty How to Get Rid of Acne: Scientifically Proven Methods...
- H Health and Medicine Simple Ways to Lower Cholesterol in the Blood: Tips and Tricks...
- O Other How to Choose the Best Answer to Your Question on The Grand Question ?...
- L Leisure and Entertainment History of International Women s Day: When Did the Celebration of March 8th Begin?...
- S Style and Beauty Intimate Haircut: The Reasons, Popularity, and Risks...
- A Art and Culture When Will Eurovision 2011 Take Place?...
- S Style and Beauty How to Choose the Perfect Hair Straightener?...
Answers on questions: Mathematics
- M Mathematics Daniela hit a golf ball from ground level. The function h=80t−16t2 represents the height of the ball in feet, where t is the time in seconds after Daniela hit it....
- M Mathematics At the point of tangency, the functions value and the local linear approximation of a function have the same value True or false...
- M Mathematics David hikes 2 ¼ miles in ½ an hour. a. What is his rate in miles per hour? b. At this rate, how long will it take him to walk 18 miles? c. If he walks for 7 hours,...
- B Biology Which of the following are amniotes? O Birds, reptiles, and amphibians O Reptiles, birds, and dogs O Cnidarians, reptiles, and mammals O Amphibians, birds, and...
- M Mathematics Find the value of x. x 13 39...
- W World Languages Rispondi alle seguenti domande 1.che cos è la chanson de roland? 2.qual è la sua struttura? 3.che cos è il ciclo carolingio? 4.qual è la trama della chanson de...
- M Mathematics What is the probability of the following, (for each answer, enter an exact number) (A) an event A that is certain to occur...
Ответ:
Probabilities are used to determine the chances of an event.
To get a B or higher, a student needs to score at least 69.76
The given parameters are:
From the z-table,
The z score of the first quartile is:
The z score formula is:
So, we have:
Rewrite as:
To get 30% or above, it means that the p value is:
The z value at
is
Recall that
Substitute
,
and ![\mathbf{\sigma= 14.93}](/tpl/images/0355/1230/c3940.png)
So, we have:
Cross multiply
Make x the subject
Hence, to get a B or higher, a student needs to score at least 69.76
Read more about probabilities at:
link
Ответ:
To get a B or higher, you need to get a grade of at least 69.77.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by
After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X. Subtracting 1 by the pvalue, we This p-value is the probability that the value of the measure is greater than X.
In this problem, we have that
Mean of 62, so![\mu = 62](/tpl/images/0355/1230/21269.png)
Q1 of 52 means that the z score of X = 52 has a pvalue of 0.25. Z has a pvalue of 0.25 between -0.67 and -0.68, so we use![Z = -0.675](/tpl/images/0355/1230/c21df.png)
Multiplying the equality by (-1), we have that:
If the instructor wishes to assign B's or higher to the top 30% of the students in the class, what grade is required to get a B or higher?
Those are the Z scores that have a pvalue higher than 0.70. So we have to find X when Z has a pvalue of 0.70. This is between 0.52 and 0.53, so we use![Z = 0.525](/tpl/images/0355/1230/df427.png)
To get a B or higher, you need to get a grade of at least 69.77.
Ответ:
What's the original problem???