Suppose we have three independent groups: X1, X2 and X3, and the population standard deviations are known as σ1 = σ2 = σ3 = 10. For each group, we observe 50 samples, and x ̄1 = 200, x ̄2 = 190, and x ̄3 = 210. Construct a 90% confidence interval for μ1 + μ2 + μ3.

Heights (cm) and weights (kg) are measured for 100 randomly selected adult males, and range from heights of 137 to 189 cm and weights of 37 to 150 kg. Let the predictor variable x be the first variable given. The 100 paired measurements yield x = 167.50 cm, y =81.41 kg, r=0.232, P-value = 0.020, and y = - 109 + 1.17x. Find the best predicted value of y (weight) given an adult male who is 145 cm tall. Use a 0.01 significance level. The best predicted value of y for an adult male who is 145 cm tall is kg. (Round to two decimal places as needed.)

Given two independent random samples with the following results: n1=10x‾1=89s1=19�1=10�‾1=89�1=19   n2=17x‾2=128s2=28�2=17�‾2=128�2=28 Use this data to find the 90%90% confidence interval for the true difference between the population means. Assume that the population variances are equal and that the two populations are normally distributed. Copy Data Step 1 of 3 :   Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

Heights (cm) and weights (kg) are measured for 100 randomly selected adult males, and range from heights of 137 to 192 cm and weights of 40 to 150 kg. Let the predictor variable x be the first variable given. The 100 paired measurements yield x = 167.80 cm, y = 81.45 kg, r=0.211, P-value = 0.035, and y = -103 +1.07x. Find the best predicted value of ŷ (weight) given an adult male who is 145 cm tall. Use a 0.01 significance level. The best predicted value of y for an adult male who is 145 cm tall is (Round to two decimal places as needed.) kg.

A sample of n=25 scores has a mean of M=68. Find the z-score for this sample: If it was obtained from a population with m=60 and s=10. If it was obtained from a population with m=60 and s=20.   If it was obtained from a population with m=60 and s=40.   A normal distribution has a mean of μ = 54 and a standard deviation of σ = 6. What is the probability of randomly selecting a score less than X = 51? What is the probability of selecting a sample of n = 4 scores with a mean less than M = 51?   What is the probability of selecting a sample of n = 36 scores with a mean less than M = 51?   A sample is selected from a population with a mean of and a standard deviation of . If the sample has scores, what is the expected value of  and the standard error of   If the sample has scores, what is the expected value of  and the standard error of ?   A random sample is obtained from a normal population with a mean of and a standard deviation of . The sample mean is   Is this a…

Independent samples of size n1 = 25 and n2 = 36 are taken from two normal populations with knownstandard deviations of σ1 = 5.5 and σ2 = 4.2. ‹e sample means are x¯1 = 13.6 and x¯2 = 19.2. Find a95% confidence interval for µ1 − µ2.

Heights (cm) and weights (kg) are measured for 100 randomly selected adult males, and range from heights of 138 to 190 cm and weights of 40 to 150 kg. Let the predictor variable x be the first variable given. The 100 paired measurements yield x = 167.88 cm, y = 81.51 kg, r=0.195, P-value = 0.052, and y= - 105 + 1.05x. Find the best predicted value of y (weight) given an adult male who is 184 cm tall. Use a 0.01 significance level. The best predicted value of y for an adult male who is 184 cm tall is kg. (Round to two decimal places as needed.)

Suppose that we would like to test the following hypotheses on the population correlation coefficient ρ: H0: ρ ≤ 0 and H1: ρ > 0. The sample correlation coefficient (r) for a sample with 7 observations (n = 7) on x and y is 0.35 . Then the test statistic t has a value of

A random sample of 130 observations produced a mean of I = 23.5 and a standard deviation s = 2.16. (a) Find a 90% confidence interval for u (b) Find a 95% confidence interval for u (c) Find a 99% confidence interval for u