# Questions on Algebra: Probability and statistics answered by real tutors!

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 Algebra: Probability and statistics Solvers Lessons Answers archive Quiz In Depth

 Question 633818: By measuring the amount of time it takes a component of a product to move from one workstation to the next, an engineer has estimated that the standard deviation is 3.33 seconds. Answer each of the following (show all work): (A) How many measurements should be made in order to be 90% certain that the maximum error of estimation will not exceed 1.0 seconds? (B) What sample size is required for a maximum error of 0.5 seconds? Click here to see answer by ewatrrr(10682)

 Question 633821: 1. A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children. A sample of 180 was taken, and the mean amount spent was \$219.76. Assuming a standard deviation equal to \$41.77, find the 99% confidence interval for m, the mean for all such families (show all work). 2. Assume that a sample is drawn and z(α/2) = 1.65 and σ = 15. Answer the following questions: (A)If the Maximum Error of Estimate is 0.05 for this sample, what would be the sample size? (B)Given that the sample Size is 400 with this same z(α/2) and σ, what would be the Maximum Error of Estimate? (C) What happens to the Maximum Error of Estimate as the sample size gets larger? (D) What effect does the answer to C above have to the size of the confidence interval? Click here to see answer by stanbon(57387)

 Question 633833: A 99% confidence interval estimate for a population mean was computed to be (29.2, 46.6). Determine the mean of the sample, which was used to determine the interval estimate (show all work). Click here to see answer by ewatrrr(10682)

 Question 633843: Determine the level of the confidence given the confidence coefficient z(α/2) for the following situation: z(α/2) = 2.58 Click here to see answer by ewatrrr(10682)

 Question 633849: What is the distance between the two points (3, 2) and (–5, 6)? Which answer is it? a. square root 90 units b. square root 80 units c. square root 45 units d. square root 20 units Click here to see answer by ewatrrr(10682)

 Question 633854: distinguish between a population and a sample Click here to see answer by Edwin McCravy(8909)

 Question 633846: 2. A study is conducted to determine if adults over 50 years old with higher total cholesterol levels are more hostile than those with lower cholesterol levels. Click here to see answer by solver91311(16897)

 Question 633873: Find the standard deviation o for the binomial distribution which has the stated value of n and p round to nearest hundredth n=45 p= 0.2 Click here to see answer by jim_thompson5910(28598)
 Question 633873: Find the standard deviation o for the binomial distribution which has the stated value of n and p round to nearest hundredth n=45 p= 0.2 Click here to see answer by stanbon(57387)

 Question 633853: for a group of four men , the probability distribution for the number x who live through the next year is as given in the accompanying table. find out the mean and the standard deviation x | p(x) 0 | 0.05 1 | 0.15 2 | 0.45 3 | 0.25 4 | 0.10 Click here to see answer by stanbon(57387)

 Question 633898: The names of 8 males and 24 females are placed into a jar for a prize drawing. Two names are drawn from the jar without replacement. What is the probability of a male name being drawn on the first draw and a female name being drawn on the second draw? Click here to see answer by reviewermath(534)

 Question 633911: A researcher claims that the average age of people who buy lottery tickets is 64. A sample of 30 is selected and their ages are recorded as shown below. The standard deviation is 9. At a = 0.05 is there enough evidence to reject the researcher’s claim? Show all work. 49 63 90 52 22 80 72 56 82 56 24 46 70 74 70 61 65 71 39 74 79 76 71 49 62 68 71 67 69 45 Click here to see answer by reviewermath(534)

 Question 633937: If the correlation coefficient is -0.275, what is the sign of the slope of the regression line? - As the correlation coefficient increases from -0.85 to -0.80, do the points of the scatter plot move toward the regression line, or away from it? Click here to see answer by stanbon(57387)

 Question 633943: Convert the following real scores into standard scores. Given: mean=9.25 and standard deviation= 2.14 a. x=10 b. x=12 c.x=6 Click here to see answer by stanbon(57387)
 Question 633943: Convert the following real scores into standard scores. Given: mean=9.25 and standard deviation= 2.14 a. x=10 b. x=12 c.x=6 Click here to see answer by solver91311(16897)

 Question 634051: a random variable X has the following probability distribution. x|1|2|3|4|5| p(x=x)|1/15|a|1/5|b|1/3| if E(x)=11/3 find the values of a and b Click here to see answer by ewatrrr(10682)

 Question 634142: Find the correlation coefficient for the data. - Find the equation for the regression line for the data, and predict the final grade of a student who misses 3.5 days. Number of absences Final Grade 0 95 1 91 2 82 3 69 4 67 5 58 Click here to see answer by ewatrrr(10682)

 Question 634154: In the poker game Texas hold em each player is dealt two cards. A flush draw is when both cards are of the same suit. What is the probability of being dealt two spades? (a spades flush draw) What is the probability of being dealt a flush draw (in any of the 4 suits)? Click here to see answer by stanbon(57387)

 Question 634174: The amount of liquid a paper towel can absorb will be use to marked the paper towel. Suppose a sample of 15 new towels average 12.5 grams with standard deviation of 1.15 grams. the previous version of this paper towel absorbed an average of 12 grams. With the =5%, we can conclude that, on average the new towel absorbs more than the previous one since the critical test value is 1.645 the new towel absorbs more than the previous one since the critical test value is 1.761 the new towel does not absorb more than the previous one since the critical test value is 1.761 the new towel does not absorb more than the previous one since the critical test value is 1.645 Click here to see answer by stanbon(57387)

 Question 634173: The amount of liquid a paper towel can absorb will be use to marked the paper towel. Suppose a sample of 15 new towels average 12.5 grams with standard deviation of 1.15 grams. the previous version of this paper towel absorbed an average of 12 grams. Calculate the test statistics for this problem t=1.6839 z=1.6839 z=0.4348 t=0.4348 Click here to see answer by stanbon(57387)

 Question 634186: A bag contains five purple ("P") blocks and one yellow ("Y") blocks. Without looking into the bag you reach in, take out a block, return the block to the bag, and then repeat the same process a number of times. Which of the following sequences of selected blocks is more likely? YPPYPP YYYPPP YYYPP Click here to see answer by stanbon(57387)

 Question 634191: The college Physical Education Department offered an Advanced First Aid course last summer. The scores on the comprehensive final exam were normally distributed, and the z scores for some of the students are shown below. Robert, 1.16 Juan, 1.87 Susan, –2.2 Joel, 0.00 Jan, –0.89 Linda, 1.78 If the mean score was μ = 151 with standard deviation σ = 15, what was the final exam score for each student? (Round your answers to the nearest whole number.) Joel = ________ Jan = ________ Juan = ________ Susan = ________ Click here to see answer by ewatrrr(10682)

 Question 634196: At General Hospital, nurses are given performance evaluations to determine eligibility for merit pay raises. The supervisor rates the nurses on a scale of 1 to 10 (10 being the highest rating) for several activities: promptness, record keeping, appearance, and bedside manner with patients. Then an average is determined by giving a weight of 3 for promptness, 1 for record keeping, 2 for appearance, and 4 for bedside manner with patients. What is the average rating for a nurse with ratings of 8 for promptness, 7 for record keeping, 7 for appearance, and 10 for bedside manner? (Round your answer to one decimal place.) Click here to see answer by richwmiller(9143)
 Question 634196: At General Hospital, nurses are given performance evaluations to determine eligibility for merit pay raises. The supervisor rates the nurses on a scale of 1 to 10 (10 being the highest rating) for several activities: promptness, record keeping, appearance, and bedside manner with patients. Then an average is determined by giving a weight of 3 for promptness, 1 for record keeping, 2 for appearance, and 4 for bedside manner with patients. What is the average rating for a nurse with ratings of 8 for promptness, 7 for record keeping, 7 for appearance, and 10 for bedside manner? (Round your answer to one decimal place.) Click here to see answer by ewatrrr(10682)

 Question 634150: If the pay outs on a superfecta bet are 3000 to 1 what is your expected winnings for a bet of \$2? Click here to see answer by rfer(12670)

 Question 634197: if family budget is 28000.whats percentage for each item.food 7560 housing 8960 transportation 3080 clothing 2520 utilities 840 health care 2240 personal needs 1680 recreation 1120 .???? Click here to see answer by ewatrrr(10682)

 Question 634193: The following table shows the Myers-Briggs personality preferences for a random sample of 406 people in the listed professions. E refers to extroverted and I refers to introverted. Personality Type Occupation EI Row Total Clergy (all denominations) 67 40 107 M.D. 67 95 162 Lawyer 56 81 137 Column Total 190 216 406 Use the chi-square test to determine if the listed occupations and personality preferences are independent at the 0.05 level of significance. (a) What is the level of significance? = ________ (b) Find the value of the chi-square statistic for the sample. (Round the expected frequencies to at least three decimal places. Round the test statistic to three decimal places.) = ________ What are the degrees of freedom? (c) Find or estimate the P-value of the sample test statistic. (Round your answer to three decimal places.) Click here to see answer by stanbon(57387)

 Question 634280: For the least-squares line yhat = 5 + 5x, what is the marginal change in yhat for each unit change in x? Click here to see answer by stanbon(57387)

 Question 634294: How many different permutation can be made from letters of the word "CURRICULUM"? Click here to see answer by Edwin McCravy(8909)

 Question 634282: Intersection and conditional probability Suppose that a certain college class contains students. Of these, are juniors, are history majors, and are neither. A student is selected at random from the class. (a) What is the probability that the student is both a junior and a history major? (b) Given that the student selected is a junior, what is the probability that she is also a history major? Write your responses as fractions. (If necessary, consult a list of formulas.) Click here to see answer by lynnlo(4164)

 Question 634289: Suppose a business owner has a choice of five locations in which to establish her business . She decides to rank each location according to certain criteria, such as price of the store and parking facilities. How many different ways can she rank five cities? Click here to see answer by lynnlo(4164)

 Question 634293: In how many ways can eight books be arranged in a shelf if they can be selected from ten books? Click here to see answer by ewatrrr(10682)

 Question 634341: Find the standard score (z) such that the area above the mean and below z is about 34% of the area under the normal curve. Click here to see answer by ewatrrr(10682)

 Question 634340: Using the z(α) notation (identify the value of α used within the parentheses). Area = 0.92 to the left of z Click here to see answer by ewatrrr(10682)

 Question 634339: Two voters were asked if they are in favor or against the "Charter Change" (cha-cha) of the present administration. The responses are Y=yes, N=no, and S=sometimes. a. Write the sample space on the possible outcome of their response. b. Find the probability that exactly 1 said yes. c. Find the probability that at least 1 said sometimes. d. Find the probability that at most 2 said no. Click here to see answer by ewatrrr(10682)

 Question 634292: How many different ways can a chairperson and an assistant chairperson be selected for a research project if there are seven scientists available? Click here to see answer by ewatrrr(10682)

 Question 634290: How many different arrangements of three boxcars can be selected from eight boxcars for a train? The order is important since each boxcar is to be delivered to a different location? Click here to see answer by ewatrrr(10682)

 Question 634279: In some reports, the mean and coefficient of variation are given. For instance, one report gives the average number of physician visits by males per year. The average reported is 3.2, and the reported coefficient of variation is 1.4%. Use this information to determine the standard deviation of the annual number of visits to physicians made by males. (Round your answer to three decimal places.) Click here to see answer by ewatrrr(10682)

 Question 634250: 1. A meal at a certain restaurant consists of 3 entrees chosen from a group of 15 possible entrees, find the number of possible meal combinations. So I tried multiply 3 by 15 and that didn't work and I tried multiplying 1/15 x 1/15 x 1/15. I know the possible answers are: 2,730 6 455 or 217,945,728,000 Your help is greatly appreciated! Thank you. Click here to see answer by ewatrrr(10682)

 Question 634248: The number of cell phone minutes used by high school seniors follows a normal distribution with a mean of 500 and a standard deviation of 50. 1.What is the probability that a student uses fewer than 600 minutes? 2.What is the probability that a student uses fewer than 400 minutes? 3.What is the probability that a student uses more than 350 minutes? 4.What is the probability that a student uses more than 580 minutes? Click here to see answer by ewatrrr(10682)

 Question 634421: Use Table 4 of the appendix to find tc for a 0.95 confidence level when the sample size is 18 Click here to see answer by Alan3354(30993)

 Question 634253: The monthly number of permits granted for building houses in a large city is seasonal (there tend to be more permits granted for construction during spring and summer months than during winter months). The following table shows the monthly seasonal indexes for building permits: JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC 0.80 0.84 0.91 1.14 1.36 1.25 1.15 1.08 0.89 0.91 0.88 0.82 Using several years of permit data, beginning in February of 2000 (i.e., t=1 corresponds to February of 2000), an analyst reported that the trend line that describes the monthly permit data is of the form Tt = 717+5t. Assuming that a multiplicative model can be used to describe the building permit data, generate a forecast for the number of building permits that you expect will be granted in June of 2005. Click here to see answer by stanbon(57387)

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