Question

In: Statistics and Probability

Let X equal the excess weight of soap in a "1000-gram" bottle. Assume that the distribution...

Let X equal the excess weight of soap in a "1000-gram" bottle. Assume that the distribution of XN(μ,180).

What sample size is required so that we have 95% confidence that the maximum error of the estimate of μ is 1.7?

Sample size required= ?

Solutions

Expert Solution

given , σ² =180

σ=√σ² = √180 = 13.4164

sampling error ,    E =   1.7                  
Confidence Level ,   CL=   95%                  
                          
alpha =   1-CL =   5%                  
Z value =    Zα/2 =    1.960   [excel formula =normsinv(α/2)]              
                          
Sample Size,n = (Z * σ / E )² = (   1.960   *   13.4164 /   1.7   ) ² =   239.3
                          
                          
So,Sample Size needed=       240                  


Related Solutions

6. Let X equal the weight (in pounds) of a “12-ounce” can of buttermilk biscuits. Assume...
6. Let X equal the weight (in pounds) of a “12-ounce” can of buttermilk biscuits. Assume that the distribution of X is approximately normally distributed. We measure 18 net weights and find out that the sample mean is 11.3 and sample standard deviation is 4. Find a 95% confidence interval for µ. (Hint: use tdistribution) A. 1.45 B. 1.96 C. 2.10 D. 7.07 E. 5.21
4. Let X equal the weight (in grams) of a Hershey’s grape-flavored Jolly Rancher. Denote the...
4. Let X equal the weight (in grams) of a Hershey’s grape-flavored Jolly Rancher. Denote the median of X by m. We wish to test the null hypothesis H0 : m = 5.900 against the alternative Ha : m > 5.900. A random sample of size n = 25 yielded the following ordered data: 5.625 5.665 5.697 5.837 5.863 5.870 5.878 5.884 5.908 5.967 6.019 6.020 6.029 6.032 6.037 6.045 6.049 6.050 6.079 6.116 6.159 6.186 6.199 6.307 6.387 Explain...
Let X be the weight of a randomly selected 10oz bag of chips. Suppose that X...
Let X be the weight of a randomly selected 10oz bag of chips. Suppose that X has a normal distribution with a mean of 10.2 and standard deviation of .05. Find the weight of x* so that 95% of all 10oz bags have a weight of at least x*.
Let X represent the weight of the students at a university. Suppose X has a mean...
Let X represent the weight of the students at a university. Suppose X has a mean of 75 kg and a standard deviation of 10 kg. Among 100 such randomly selected students from this university, what is the approximate probability that the average weight of this sample (X100) lies between (a) 74 and 75 kg (b) greater than 76 kg (c) less than 73 kg Assume that the sample size(N) is large enough for the CLT (Central Limit Theorem) to...
We usually assume that your weight as measured by a scale is equal to the magnitude...
We usually assume that your weight as measured by a scale is equal to the magnitude of the gravitational force that the earth exerts on you. Because of the rotation of the earth, however, the scale reading can actually be slightly different from your true weight. Which of the following accurately describes this effect?
X is a random variable for losses. X follows a beta distribution with θ = 1000,...
X is a random variable for losses. X follows a beta distribution with θ = 1000, a = 2, and b = 1. Calculate TVaR0.90(X)
Let X be a random variable that is equal to the number of times a 5...
Let X be a random variable that is equal to the number of times a 5 is rolled in three rolls of a fair 5-sided die with the integers 1 through 5 on the sides. What is E[X2 ]? What is E2 [X], that is, (E[X])2 ? Justify your answers briefly
Suppose X has a normal distribution with mean equal to 80 and standard deviation equal to...
Suppose X has a normal distribution with mean equal to 80 and standard deviation equal to 12. Use Table 3 from the appendix (the normal distribution table) to calculate the 10th percentile, 20th percentile, 50th percentile, 80 percentile and 90th percentile of X.Percentile 10 20 50 80 90
A. Let f(x) be: x+(12/(1-x)) if x is less than or equal to -3 x+3 if...
A. Let f(x) be: x+(12/(1-x)) if x is less than or equal to -3 x+3 if -3 < x and x is less than or equal to zero ln(x) if 0< x is less than equal to 5 (x-5)/5+ln5 if x>5 answer and explain these answers B. Is f differentialble at x=5? justify your answer by evaluating the one sided limits of lim as x approches 5 (f(x)-f(5))/x-5
Let X follow Demoivre with ω. Find the distribution of T(x) Let Z represent the present...
Let X follow Demoivre with ω. Find the distribution of T(x) Let Z represent the present value random variable representing benefit of $1 payable at the moment of death for a whole life insurance sold to (x)- a person age x. Calculate E(Z) and Var(Z). Let W represent the present value random variable representing benefit of $1 payable at the end of year of death for a whole life insurance sold to (x)- a person age x. Calculate E(W) and...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT