Ap statistics homework help!?
A school system employs teachers at salaries between $30,000 and $60,000. The teachers union and the school board are negotiating the form of next years increase in the salary schedule. Suppose that every teacher is given a flat $1000 raise. How much will the mean salary increase? The median salary?
AP Statistics homework help?
I was absent the day my class learned this, so I m a little confused. In 1990, 5.8% of job applicants who were tested for drugs failed the test. a) Give a 99.8% confidence interval for the percent of drug test failures for a random sample of 400 job applicants. b)How many fewer samples could be used if the margin of error remained the same as in part “b” but for a 90% confidence interval?
AP Statistics Homework Help?
1. In terms of z-scores, the first quartile (Q1) is at z = -.6745. The third quartile is at z = .6745. Thus the IQR in a normal distribution is 2(.6745) = 1.35. If we multiply this by 1.5 and add it to .6745, we get 2.7. The area to the right of 2.7 under the standard normal curve is .003467. Double this to account for the left-hand side as well to get .006934. Thus, the area you are searching for is roughly .7%. 2. Let u = mean and s = sigma. Also, the bottom 40% of the standard normal curve corresponds to a z-score of -.2533. And the top 2% of the standard normal curve corresponds to a z-score of 2.054. Now we have the following equations: -.2533 = (1 - u)/s & 2.054 = (2 - u)/s This is a system of equations problem. Solve both for s: s = (1 - u)/-.2533 & s = (2 - u)/2.054 Since they are both equal to s, they are both equal to each other: (1 - u)/-.2533 = (2 - u)/2.054 Cross multiply: 2.054(1 - u) = -.2533(2 - u) Distribute: 2.054 - 2.054u = -.5066 + .2533u Collect like terms: -2.054u - .2533u = -.5066 - 2.054 -2.3073u = -2.5606 u = 2.5606 / 2.3073 = 1.11 minutes <----this is the mean Now find the standard deviation: s = (2 - 1.11) / 2.054 = .4333 minutes <----this is the standard deviation
AP Statistics Homework Help?
1) Enzo is deciding whether to purchase a regular or a standby bus ticket. Each time Enzo travels on a bus, he either arrives at his destination on time or is delayed. The standby ticket is less reliable, but it gives Enzo more value when it does work because it is cheaper. Enzo collected data on 200 of each type of bus ticket. Once Enzo decides which type of ticket to purchase, he plans to purchase 10 tickets. What is Enzo’s expected value if he purchases regular tickets? $ What is Enzo’s expected value if he purchases standby tickets? $ To maximize his expected value, Enzo should purchase bus tickets. (If necessary, round your answers to the nearest cent.) The following table shows the value that Enzo gets from each type of ticket depending on whether he arrives at his destination on time or is delayed. Regular ticket Standby ticket On time $20 $40 Delayed $5 $15 The following table shows the data Enzo collected on each type of ticket. Bus status Regular ticket Standby ticket On time 167 146 Delayed 33 54 Total 200 200 2) Pooja and Amit are playing a card game with a standard 52 card deck. Pooja will draw a card. If the card she draws is a face card (a jack, queen, or king), she will win $6. If Pooja draws an ace, she will win $4. If any other card is drawn, she will lose $2. What is Pooja's expected value of playing this game? Round your answer to the nearest cent.
AP statistics homework question?
can someone please help me? it's graded for correctness An insurance company advertises that 90% of their accident claims are settled within 30 days. A consumer group randomly selects 104 of last year's claims from the company's files, and finds that only 89 of them were settled within 30 days. Is the company guilty of false advertising? THANKS!!
AP statistics homework question. Help Please?
You have: X~N(4, 0.01) sdev=0.1 => var(x)=0.01 Y~N(4.2, 25e-4) a) let Z=X-Y, since both X and Y are normally distributed random variable, then there sum (or difference) is also a normal distribution. So Z is a normal random variable. Than you need to find the mean of Z (center), and the spread(stdev or variance). E(Z) = E(X-Y) = E(X)-E(Y) = 4-4.2 = -0.2 inches Var(Z) = Var(X-Y) = Var(X) + Var(Y) = 0.01 + 25e-4 = 1.25e-2 SDEV(Z) = sqrt(Var(Z)) = 0.11 inches Z is the random variable that the CD will fit in the case. b) if the diameter of the CD is less than the diameter of the case, than it will fit: P(X<=Y) = P(X-Y<=0) = P(Z<=0) = P( (Z-E(Z))/SD(Z) <= 0+0.2/0.11) = phi(0.2/0.11) = phi(1.82) = 0.9656. This means that 96.56% of his CDs will fit in the case. c) let 1-p=0.9656 the probability of the CD fitting in the case, than p is the probability that it's not fitting in the case. The problem here is whether the CD will fit or not in the CASE (Z<0 each time). So you have a binary random variable repeated 100 times. Let H be that variable. H~B(100,1-p) (binomiale law) which I think can be approximated with the centered reduced normal distribution. I am not sure though but I believe your formula is: phi(0.5-np/sqrt(np(1-p) ) this will give you phi(1.61) = 0.9452 d) I have no clue
AP Statistics Homework Help Please?
In the following exercise you are to use the binomial probability formula to answer the question . Begin with the formula, and show substitution into the formula. -Suppose you purchase a bundle of 10 bare-root broccoli plants. The sales clerk tells you that on average you can expect 5% of the plants to die before producing any brocolli. Assume that the bundle is a random sample of plants. Use the binomial formula to find the probability that you will lose at most 1 of the broccoli plants. -In 1998, Mark Mcgwire of the st. Louis Cardinals hit 70 home runs, new record. Was this feat as surprising as most of us thought? In the 3 seasons before 1998, Mcgwire hit a home run in 11.6% of his times at bat. He went to bat 509 times in 1998. Mcgwires homerun count in 509 times at bas has approximately the binomial distribution with n=509 and p=0.116. What is the mean # of home runs he will hit in 509 times at bat? What is the probability of 70 or more home runs? *Thank you ever so much!!
AP Statistics Homework Help Please? pt II?
A mechanical assembly (Figure 7.12) consists of a shaft with a bearing at each end. The total length of the assembly is the sum X + Y + Z of the shaft length X and the lengths Y and Z of the bearings. These lengths may vary from part to part in production, independently of each other and with normal distributions. The shaft length X has mean 11.6 inches and standard deviation of 0.001 inch, while each bearing length Y and Z has a mean 0.5 inch and standard deviation 0.003 inch. Figure 7.12 - LINK: http://i257.photobucket.com/albums/hh201/reeserpie/figure-07-12.jpg (b) It is a common practice in the industry to state the "natural tolerance" of parts in the form used in part (a). An engineer who know no statistics thinks that tolerances add, so that the natural tolerance for the total length of the assembly (shaft and two bearings) is 12 d inches, where d = d1 + 2 d2. Find the standard deviation of the total length X + Y + Z. ** thank you very much!!!
Histograms? Please help with Statistics homework! ?
I have several problems like this to do and don't understand it very well. I have read the literature over and over and still don't understand how to manually draw a histogram. The example I have makes no sense either. Help would greatly be appreciated. (a) Find the Class Width (b) Make a frequency table showing limits, class boundries, midpoints, frequencies, and relative frequencies. (c) Draw a histogram (d) Draw a relative frequency-histogram The following data represents glucose blood levels (mg/100 ml) after a 12-hour fast for a random sample of 70 women 45 66 83 71 76 64 59 59 76 82 80 81 85 77 82 90 87 72 79 69 83 71 87 69 81 76 96 83 67 94 101 94 89 94 73 99 93 85 83 80 78 80 85 83 84 74 81 70 65 89 70 80 84 77 65 46 80 70 75 45 101 71 109 73 73 80 72 81 63 74 Use six classes
Can I get help with Physics homework?
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