




Card 11 / 24:
Marketing companies have collected data implying that teenage girls use more ring tones on their cellular phones than teenage boys do. In one particular study of 40 randomly chosen teenage girls and boys (20 of each) with cellular phones, the mean number of ring tones for the girls was 3.2 with a standard deviation of 1.5. The mean for the boys was 1.7 with a standard deviation of 0.8. Conduct a hypothesis test to determine if the means are approximately the same or if the girls’ mean is higher than the boys’ mean.
The course author didn't provide an answer for this question

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Questions & Answers
what percent of the students would be expected to score above 95?
inferential statistics is what?
in which we make infrences (hypothsis)
asad
surpose a data set of 2,3,5,6,1,4 are given find median
fastest finger please
lucy
Mean (average) 4...
Median (middle term) 3.5..
Mode (frequency) every element in a set has 1 frequrncy
Akash
i arrange the data set in ascending order. that is, 1,2,3,4,5,6. then find the data set that falls in the middle. in this case, 3 & 4 fall in the middle. you then sum and obtain the average. that is, (3+4)/2=3.5. therefore, 3.5 is the median.
Gbenga
both of you are correct.
Joseph
how does a line graph look
King
pls who knows how line graph look like
King
line graph usually have a straight line running through axis
Dike
am new here anyone willing to orient me?
Timothy
find the media of the following numbers 61,64,67,70,73
what happen to your body@hana
Benmike
what is the percentile for the set of data in the class C and frequency F(c,f)given by (9.39.7,2) (9.810.2,5) (10.310.7,12) (10.811.2,17) (11.311.7,14) (11.812.2,6) (12.312.7,3) (12.813.2,1)
arrange ascending and desending order than the mid value is Median
rajendra
what if it is a group data
Oloyede
mean/ medium/ mode
Michelle
An operational manager at a manufacturing company is interested in the level of satisfaction of computer buyers. The manager has developed a satisfaction scale of 110 to mark their level of understanding with the company.What is the population of the interest?
how to use grouped and ungrouped data
by dividing 11.37 on 2
saifuddin
by dividing 11.34 on 2
saifuddin
what is index number?
vinayak
What is the differences between quota an lottery system of sampling
EGBE
What are the are the characteristics that are critically expedients in selecting the sample size
EGBE
fit a binomial distribution for the following data and test the goodness of fit
x: 0 1 2 3 4 5 6
f: 5 18 28 12 7 6 4
solve the question please
Mano
can some please help solve so that we learn some
Simonsakala
It is a square chi
Nelson
But can't be a binomial because, the x numbers are 0 to 6, instead those would be "0" or "1" in a straight way
Nelson
You can do a chisquare test, but the assumption has to be a normal distribution, and the last f's number need to be "64"
Nelson
sorry the last f's numbers : "6 and 4" which are the observed values for 5 and 6 (expected values)
Nelson
can't understand basic of statistics ..
rajendra
Sorry I see my mistake, we have to calculate the expected values
Nelson
So we need this equation:
P= (X=x)=(n to x) p^x(1p)^nx
Nelson
why it is not possible brother
ibrar
were n= 2 ( binomial) x= number of makes (0 to 6) and p= probability, could be 0.8.
Nelson
so after we calculate the expected values for each observed value (f) we do the chisquare. x^2=summatory(observedexpected)^2 / expected
and compare with x^2 in table with 0.8
Nelson
tomorrow I'll post the answer, I'm so tired today, sorry for my mistake in the first messages.
Nelson
It is possible, sorry for my mistake
Nelson
two trader shared investment and buoght Cattle.Mr.Omer bought 255 cows & rented the farm for a period of 32 days. Mr. Ahmed grazed his Cattle for 25 days. Mr. Ahmed's cattle was 180 cows.Together they profited $ 7800. the rent of the farm is $ 3000 so divide the profit per gows/day for grazing day
Mohamed
how to start this book, who is reading thins first time
It is my first time reading this book
Qader
from were did you get 2/50?m
Why do you think that is?
Jazzy
because there is an increase in number of people with age more than 30.
Qader
Ok. And what do you think is the driving factor behind that hypothesis?
Jazzy
fewer birth and increase in # of years living or fewer dying
Qader
What about the improvement of technology and medicine?
Jazzy
please help me, with this.... three coins are tossed let be the number of head(h)obtain,construct a probability distribution for X
godwin
technology and medicine is improving but they are limited
Ayunku
If those conscience of their health, one will live longer periods of life.
Montrae
hi,why the mean =sum(xi)/n but the variance =sum(xixbar)/ n1
what is the difference between (n or n1)
This is hard to type, so I'll use "m" for "x bar", and a few other notations that I hope will be clear: Definition: sqrt(SUM[(x  m)^2] / (n1)) where m = SUM[x] / n Desired formula: sqrt((SUM[x^2]  SUM[x]^2)/n / (n1)) Now let's do what you started to do, and see if we can manipulate the definitio
Michael
what is the difference between (n ) and (n1) in the mean and variance
Soran
Definition: sqrt(SUM[(x  m)^2] / (n1)) where m = SUM[x] / n
what is the difference between (n and n1)
Soran
Hi, the diference is tha when we estimate parameters in a sample (not in the total population) we need to consider the degrees of liberty for the estimation.
Nelson
Hie guys, am analysing rainfall data for different stations and i got kurtosis values of 0.7 for one station and 0.4 for another, what can i say about this?
Kudakwashe
difference in degrees of freedom
vinayak
Source:
OpenStax, Introductory statistics. OpenStax CNX. May 06, 2016 Download for free at http://legacy.cnx.org/content/col11562/1.18
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