# 9.8 Exercises  (Page 4/5)

 Page 4 / 5

According to a recent survey of 1200 people, 61% feel that the president is doing an acceptable job. We are interested in the population proportion of people who feel the president is doing an acceptable job.

• Define the Random Variables $X$ and $P\text{'}$ , in words.
• Which distribution should you use for this problem? Explain your choice.
• Construct a 90% confidence interval for the population proportion of people who feel the president is doing an acceptable job.
• State the confidence interval.
• Sketch the graph.
• Calculate the error bound.

• $N\left(0.61,\sqrt{\frac{\left(0.61\right)\left(0.39\right)}{1200}}\right)$
• CI: (0.59, 0.63)
• EB = 0.02

A survey of the mean amount of cents off that coupons give was done by randomly surveying one coupon per page from the coupon sections of a recent San Jose Mercury News. The following data were collected: 20¢; 75¢; 50¢; 65¢; 30¢; 55¢; 40¢; 40¢; 30¢; 55¢; $1.50; 40¢; 65¢; 40¢. Assume the underlying distribution is approximately normal. • $\overline{x}=\text{________}$ • ${s}_{x}=\text{________}$ • $n=\text{________}$ • $n-1=\text{________}$ • Define the Random Variables $X$ and $\overline{X}$ , in words. • Which distribution should you use for this problem? Explain your choice. • Construct a 95% confidence interval for the population mean worth of coupons. • State the confidence interval. • Sketch the graph. • Calculate the error bound. • If many random samples were taken of size 14, what percent of the confident intervals constructed should contain the population mean worth of coupons? Explain why. An article regarding interracial dating and marriage recently appeared in the Washington Post . Of the 1709 randomly selected adults, 315 identified themselves as Latinos, 323 identified themselves as blacks, 254 identified themselves as Asians, and 779 identified themselves as whites. In this survey, 86% of blacks said that their families would welcome a white person into their families. Among Asians, 77% would welcome a white person into their families, 71% would welcome a Latino, and 66% would welcome a black person. • We are interested in finding the 95% confidence interval for the percent of all black families that would welcome a white person into their families. Define the Random Variables $X$ and $P\text{'}$ , in words. • Which distribution should you use for this problem? Explain your choice. • Construct a 95% confidence interval • State the confidence interval. • Sketch the graph. • Calculate the error bound. • $N\left(0.86,\sqrt{\frac{\left(0.86\right)\left(0.14\right)}{323}}\right)$ • CI: (0.823, 0.898) • EB = 0.038 Refer to the problem above. • Construct three 95% confidence intervals. • Percent of all Asians that would welcome a white person into their families. • Percent of all Asians that would welcome a Latino into their families. • Percent of all Asians that would welcome a black person into their families. • Even though the three point estimates are different, do any of the confidence intervals overlap? Which? • For any intervals that do overlap, in words, what does this imply about the significance of the differences in the true proportions? • For any intervals that do not overlap, in words, what does this imply about the significance of the differences in the true proportions? #### Questions & Answers what is math number Tric Reply x-2y+3z=-3 2x-y+z=7 -x+3y-z=6 Sidiki Reply Need help solving this problem (2/7)^-2 Simone Reply x+2y-z=7 Sidiki what is the coefficient of -4× Mehri Reply -1 Shedrak the operation * is x * y =x + y/ 1+(x × y) show if the operation is commutative if x × y is not equal to -1 Alfred Reply An investment account was opened with an initial deposit of$9,600 and earns 7.4% interest, compounded continuously. How much will the account be worth after 15 years?
lim x to infinity e^1-e^-1/log(1+x)
given eccentricity and a point find the equiation
12, 17, 22.... 25th term
12, 17, 22.... 25th term
Akash
College algebra is really hard?
Absolutely, for me. My problems with math started in First grade...involving a nun Sister Anastasia, bad vision, talking & getting expelled from Catholic school. When it comes to math I just can't focus and all I can hear is our family silverware banging and clanging on the pink Formica table.
Carole
I'm 13 and I understand it great
AJ
I am 1 year old but I can do it! 1+1=2 proof very hard for me though.
Atone
hi
Not really they are just easy concepts which can be understood if you have great basics. I am 14 I understood them easily.
Vedant
find the 15th term of the geometric sequince whose first is 18 and last term of 387
I know this work
salma
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
hmm well what is the answer
Abhi
If f(x) = x-2 then, f(3) when 5f(x+1) 5((3-2)+1) 5(1+1) 5(2) 10
Augustine
how do they get the third part x = (32)5/4
make 5/4 into a mixed number, make that a decimal, and then multiply 32 by the decimal 5/4 turns out to be
AJ
how
Sheref
can someone help me with some logarithmic and exponential equations.
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
I don't understand what the A with approx sign and the boxed x mean
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
oops. ignore that.
so you not have an equal sign anywhere in the original equation?
hmm
Abhi
is it a question of log
Abhi
🤔.
Abhi
I rally confuse this number And equations too I need exactly help
salma
But this is not salma it's Faiza live in lousvile Ky I garbage this so I am going collage with JCTC that the of the collage thank you my friends
salma
Commplementary angles
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
hii
Uday
hi
salma
hi
Ayuba
Hello
opoku
hi
Ali
greetings from Iran
Ali
salut. from Algeria
Bach
hi
Nharnhar
A soccer field is a rectangle 130 meters wide and 110 meters long. The coach asks players to run from one corner to the other corner diagonally across. What is that distance, to the nearest tenths place.
Jeannette has $5 and$10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
What is the expressiin for seven less than four times the number of nickels
How do i figure this problem out.
how do you translate this in Algebraic Expressions
why surface tension is zero at critical temperature
Shanjida
I think if critical temperature denote high temperature then a liquid stats boils that time the water stats to evaporate so some moles of h2o to up and due to high temp the bonding break they have low density so it can be a reason
s.
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
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