A recent survey found that 69% of all adults over 50 wear glasses for driving . In a random sample of 70 adults over 50, what is the mean and standard deviation of those that wear glasses? Round the answers to the nearest hundredth

Q: On the past math summative exam, the bottom 20% of students failed to pass the test. The mean for…

A: The mean for the test is, μ=55 The standard deviation is σ=11 Consider that the bottom 20% of…

Q: A random sample of 54 four-year-olds attending day care centers provided a yearly tuition average of…

A: Given n=54 X-bar=3912 Standard deviations=615

Q: A quiz consists of 20 true or false questions. If the student guesses on each question what is the…

A: Solution: Let X be the number of correct answers and n be the number of questions. Since the…

Q: On a math exam, Joel had a score o 90, which was exactly 2 standard deviations above the mean. The…

A: Since, we only do up to three sub parts of a problem, we'll be doing the first three sub parts only.…

Q: On a nationwide math test, the mean was 51 and the standard deviation was 4. If Roberto scored 70,…

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Q: On a nationwide math test, the mean was 60 and the standard deviation was 7. If Roberto scored 90,…

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Q: The reading speed of sixth-grade students is approximately normal, with a mean speed of 125 words…

A: Mean = 125 Standard deviation = 24

Q: In another company, every worker received a 5% raise. How does this affect the mean salary? The…

A: Every worker received a 5%. The mean defines that the center or average of the data and it is…

Q: what if the standard deviation was 30, instead of 60

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Q: Of the 200 American film enthusiasts, the average age is: 30 years, while the standard deviation is…

A: Normal distribution is generally denser in the center, and basically less denser at the tails. There…

Q: 95% of 80 freshman history students scored between 70% and 80% on a take home quiz. If this data is…

A: Given,  n=80 α= (1-0.95) =0.05 Let X denote the score of freshmen. As per t-distribution table, the…

Q: Isn't here the standard deviation equal to 4, not 2, as the tutor wrote?

A: Solution-: Given: μ=-3,σ=4 We want to find, P(0<X<2)=? Draw the picture.

Q: The mean grade on a science test was 79 and there was a standard deviation of 6. If your sister…

A: The z score explains the deviations of the observations from the mean. It is calculated using the…

Q: A successful basketball player has a height of 6 feet 2 ​inches, or 188 cm. Based on statistics from…

A: Given the Z score of height of basket ball player is 1.95. The original height of the basket ball…

Q: According to Chebyshev's rule, within 10 standard deviations from the mean, lies at least of any…

A: Given Information: According to Chebyshev's rule, within 10 standard deviations from the mean, lies…

Q: During 1 week, an overnight delivery company found that the weights of its parcels were normally…

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Q: A test has a mean of 140 and a standard deviation of 27. What proportion of people have scores…

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Q: Recently, a random sample of 25–34 year olds was asked, "How much do you currently have in savings,…

A: From the different savings class we need to find first the class mid point(xi) . And the frequency…

Q: If each score is increased by 25, what will be the mean and standard deviation of the distribution…

A: Given that  The distribution of raw scores on particular achievement test Mean = 500 Standard…

Q: A data set has size of 40. How many observations lie within two standard deviations of either sides…

A: The 68-95-99.7% (Empirical) Rule: For a normal distribution, the empirical rule (68-95-99.7% Rule)…

Q: On a spelling test, the standard deviation is equal to 0.94. What does this mean

A: We know that the Standard deviation tells us that how much data is scattered around the mean value…

Q: Suppose you were told you scored two standard deviation below the mean on a measure where the main…

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Q: A recent survey found that 61​% of all adults over 50 wear glasses for driving. In a random sample…

A: A recent survey found that 61​% of all adults over 50 wear glasses for driving. In a random sample…

Q: Mansoor surveyed 140 ZU male students to investigate the amount of time spent on social media per…

A: Given data isMansoor surved male students(n)=140variance(σ2)=122 minutes2

Q: If the mean is seven and the standard deviation is two, what value is three standard deviations to…

A: It is given that the The mean is 7 and the standard deviation is 2 i.e. μ =7 and σ =2. We have to…

Q: The mean grade of adrian in the final examination in mathematics was 85 and the standard deviation…

A: The mean of a dataset is computed by μ=∑xn, where ∑x is sum of observations and n is the total…

Q: In 2019, the amount of money that motorists spent on gas had a normal distribution with a mean of…

A: Given Information Number of persons sampled (n) = 2400 Mean (µ) = 900 Standard deviation(σ) = 100…

Q: Suppose a probability and statistics class took an exam that had a mean of 60 and a standard…

A: Given, E(X)=60 SD(X)=12   After 10 Point curve Let Y be new variable.

Q: On a final exam, the mean mark was 68% and the standard deviation was 12%. If John’s mark was 36%…

A: Given that on a final exam, the mean mark was 68% and the standard deviation was 12%. If John’s mark…

Q: A line for tickets to a broadway show had a mean waiting time of 20 minutes with a statistic…

A: Given: Mean,  μ=20 Standard deviation, σ=5 Sample size, n= 200 Use normal approximation here, the…

Q: 95% of 80 night students scored between 70% and 80% on a quiz. If this data is normally distributed,…

A: Given: Total number of students n=80.             let X  denote the marks of students then,  X ~N(µ,…

Q: In a Science test, the mean score is 42 and the standard deviation is 5. Assuming the scores are…

A: Given: The mean score of a Science test is μ=42. The standard deviation is σ=5. Let X be a random…

Q: in a group of 230 tests, how many students score within one standard deviation of the mean?

A: The probability that the students score within one standard deviation of the mean will be:…

Q: In a recent survey, 80% of the community favored building a police substation in their neighborhood.…

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Q: A quantitative data set has a size of 50. At least how many observations lie within seven standard…

A: Suppose X is a random variable with expectation, μ and standard deviation, σ. Then, for any positive…

Q: A test consists of 940 true or false questions. If the student guesses on each​ question, what is…

A: Given number of true or false questions = n = 940.Probability of correct answer p = 1/2Here we can…

Q: Recently, a random sample of 25–34 year olds was​ asked, "How much do you currently have in​…

A: Class Interval Frequency(f) Midpoint (x) f.x fx2 0-199 342 (0+199)/2= 99.5 34029 3385885.5…

Q: A popcorn company find that their 1kg bags have a mean of 985 grams with a standard deviation of 24…

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Q: Can you find the mean and the standard deviation?

A: To find the mean and standard deviation of the given data: Mean is the sum of observations divided…

Q: Explain the standard deviation?

A: Standard deviation: Both the standard deviation and the variance are based on how much each…

Q: A successful basketball player has a height of 6 feet 77​inches, or 201201 cm. Based on statistics…

A: Given information- Height of a player = 201 cm Z-score = 3.743 We know that standard height is given…

Q: A biologist found the wingspans of a group of monarch butterflies to be normally distributed, with a…

A: Given,Mean (μ) = 52.2Standard deviation (σ) = 2.3a) Required probability is…

Q: In a survey of women in Canada, the mean height was 65 inches with a standard deviation of 3 inches.…

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Q: A researcher in Des Moines, Iowa sampled 56 households and found the mean number of puppies per…

A: # sample size n=56  population mean mu=3.03  standard deviations=1.5  then to find 62nd percentile…

Q: The reading speed of sixth grade students is approximately normal with a mean speed of 115 word per…

A: Consider that the mean and standard deviation of a random variable X are µ and σ, respectively.…

Q: A successful basketball player has a height of 6 feet 3 ​inches, or 191 cm. Based on statistics from…

A: Given,a basketball player has a height of 6 feet 3 inchesand the Z-score =2.31

Q: A successful basketball player has a height of 6 feet 4 ​inches, or 193 cm. Based on statistics from…

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Q: A mean of 200 and a standard deviation of 50. Find P60, the score which separates the lower 60% form…

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Q: Would it be reasonable to use the standard deviation formula?

A: here  According to a gallup survey of boys 77% of boys had played computer games in the past week…