# 0.1 Review exercises (ch 3-13)  (Page 7/12)

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Pizza Hamburgers Spaghetti Fried shrimp
5th grader 15 6 9 0
6th grader 15 7 10 8

79. Find the probability that one randomly chosen child is in the 6th grade and prefers fried shrimp.

1. $\frac{32}{70}$
2. $\frac{8}{32}$
3. $\frac{8}{8}$
4. $\frac{8}{70}$

80. Find the probability that a child does not prefer pizza.

1. $\frac{30}{70}$
2. $\frac{30}{40}$
3. $\frac{40}{70}$
4. 1

81. Find the probability a child is in the 5 th grade given that the child prefers spaghetti.

1. $\frac{9}{19}$
2. $\frac{9}{70}$
3. $\frac{9}{30}$
4. $\frac{19}{70}$

82. A sample of convenience is a random sample.

1. true
2. false

83. A statistic is a number that is a property of the population.

1. true
2. false

84. You should always throw out any data that are outliers.

1. true
2. false

85. Lee bakes pies for a small restaurant in Felton, CA. She generally bakes 20 pies in a day, on average. Of interest is the number of pies she bakes each day.

1. Define the random variable X .
2. State the distribution for X .
3. Find the probability that Lee bakes more than 25 pies in any given day.

86. Six different brands of Italian salad dressing were randomly selected at a supermarket. The grams of fat per serving are 7, 7, 9, 6, 8, 5. Assume that the underlying distribution is normal. Calculate a 95% confidence interval for the population mean grams of fat per serving of Italian salad dressing sold in supermarkets.

87. Given: uniform, exponential, normal distributions. Match each to a statement below.

1. mean = median ≠ mode
2. mean>median>mode
3. mean = median = mode

## Chapter 10

Use the following information to answer the next three exercises: In a survey at Kirkwood Ski Resort the following information was recorded:

0–10 11–20 21–40 40+
Ski 10 12 30 8
Snowboard 6 17 12 5

Suppose that one person from [link] was randomly selected.

88. Find the probability that the person was a skier or was age 11–20.

89. Find the probability that the person was a snowboarder given he or she was age 21–40.

90. Explain which of the following are true and which are false.

1. Sport and age are independent events.
2. Ski and age 11–20 are mutually exclusive events.
3. P (Ski AND age 21–40)< P (Ski|age 21–40)
4. P (Snowboard OR age 0–10)< P (Snowboard|age 0–10)

91. The average length of time a person with a broken leg wears a cast is approximately six weeks. The standard deviation is about three weeks. Thirty people who had recently healed from broken legs were interviewed. State the distribution that most accurately reflects total time to heal for the thirty people.

92. The distribution for X is uniform. What can we say for certain about the distribution for $\overline{X}$ when n = 1?

1. The distribution for $\overline{X}$ is still uniform with the same mean and standard deviation as the distribution for X .
2. The distribution for $\overline{X}$ is normal with the different mean and a different standard deviation as the distribution for X .
3. The distribution for $\overline{X}$ is normal with the same mean but a larger standard deviation than the distribution for X .
4. The distribution for $\overline{X}$ is normal with the same mean but a smaller standard deviation than the distribution for X .

93. The distribution for X is uniform. What can we say for certain about the distribution for $\sum X$ when n = 50?

1. distribution for $\sum X$ is still uniform with the same mean and standard deviation as the distribution for X .
2. The distribution for $\sum X$ is normal with the same mean but a larger standard deviation as the distribution for X .
3. The distribution for $\sum X$ is normal with a larger mean and a larger standard deviation than the distribution for X .
4. The distribution for $\sum X$ is normal with the same mean but a smaller standard deviation than the distribution for X .

what is standard deviation?
It is the measure of the variation of certain values from the Mean (Center) of a frequency distribution of sample values for a particular Variable.
Dominic
Yeah....the simplest one
IRFAN
what is the number of x
10
Elicia
Javed Arif
Jawed
how will you know if a group of data set is a sample or population
population is the whole set and the sample is the subset of population.
umair
if the data set is drawn out of a larger set it is a sample and if it is itself the whole complete set it can be treated as population.
Bhavika
hello everyone if I have the data set which contains measurements of each part during 10 years, may I say that it's the population or it's still a sample because it doesn't contain my measurements in the future? thanks
Alexander
Pls I hv a problem on t test is there anyone who can help?
Peggy
Dominic
Bhavika is right
Dominic
what is the problem peggy?
Bhavika
hi
Sandeep
Hello
hi
Bhavika
hii Bhavika
Dar
Hi eny population has a special definition. if that data set had all of characteristics of definition, that is population. otherwise that is a sample
Hoshyar
three coins are tossed. find the probability of no head
three coins are tossed consecutively or what ?
umair
umair
or .125 is the probability of getting no head when 3 coins are tossed
umair
🤣🤣🤣
Simone
what is two tailed test
if the diameter will be greater than 3 cm then the bullet will not fit in the barrel of the gun so you are bothered for both the sides.
umair
in this test you are worried on both the ends
umair
lets say you are designing a bullet for thw gun od diameter equals 3cm.if the diameter of the bullet is less than 3 cm then you wont be able to shoot it
umair
In order to apply weddles rule for numerical integration what is minimum number of ordinates
excuse me?
Gabriel
why?
didn't understand the question though.
Gabriel
which question? ?
We have rules of numerical integration like Trapezoidal rule, Simpson's 1/3 and 3/8 rules, Boole's rule and Weddle rule for n =1,2,3,4 and 6 but for n=5?
John
geometric mean of two numbers 4 and 16 is:
10
umair
really
iphone
quartile deviation of 8 8 8 is:
iphone
sorry 8 is the geometric mean of 4,16
umair
quartile deviation of 8 8 8 is
iphone
can you please expalin the whole question ?
umair
mcq
iphone
h
iphone
can you please post the picture of that ?
umair
how
iphone
hello
John
10 now
John
how to find out the value
can you be more specific ?
umair
yes
KrishnaReddy
what is the difference between inferential and descriptive statistics
descriptive statistics gives you the result on the the data like you can calculate various things like variance,mean,median etc. however, inferential stats is involved in prediction of future trends using the previous stored data.
umair
if you need more help i am up for the help.
umair
Thanks a lot
Anjali
Inferential Statistics involves drawing conclusions on a population based on analysis of a sample. Descriptive statistics summarises or describes your current data as numerical calculations or graphs.
fred
my pleasure😊. Helping others offers me satisfaction 😊
umair
for poisson distribution mean............variance.
both are equal to mu
Faizan
mean=variance
Faizan
what is a variable
something that changes
Festus
why we only calculate 4 moment of mean? asked in papers.
why we only 4 moment of mean ? asked in BA exam
Faizan
Hello, can you please share the possible questions that are likely to be examined under the topic: regression and correlation analysis.
Refiloe
for normal distribution mean is 2 & variance is 4 find mu 4?
repeat quastion again
Yusuf
find mu 4. it can be wrong but want to prove how.
Faizan
for a normal distribution if mu 4 is 12 then find mu 3?
Question hi wrong ha
Tahir
ye BA mcqs me aya he teen he. 2dafa aya he
Faizan
if X is normally distributed. (n,b). then its mean deviation is?
Faizan
The answer is zero, because all odd ordered central moments of a normal distribution are Zero.
nikita
which question is zero
Faizan
sorry it is (5,16) in place of (n,b)
Faizan
I got. thanks. it is zero.
Faizan
a random variable having binomial distribution is?
Bokaho