Question

70% 2:39 PM Wed Jul 15 T + O Ex: In the example to the right we took twenty different samples of size n, and found the corresponding confidence intervals with a 95% level of confidence A 95% confidence interval indicates that out of 20 samples from the same population will produce confidence intervals that contain Ex: In a 2018 random survey of 160 American Democrats, 136 said that they support Medicare-for-all, also known as single-payer healthcare. Find the 95% confidence interval estimate for the true proportion of Democrats in America who support Medicare-for-all. Identity point estimate (sample proportion) Determine critical value Find margin of error Construct confidence interval Interpretation of CI < 4 Does the proportion of Democrats who support Medicare-for-all appear to be substantially different than the 70% rate for the general population? If so, why do you think that is? 10

Answer 1

EXA: A 19 will produce 95% confidence interval indicates that out of 2o Samples from the same population Confidence intervals that contain The true population mean . The" 5 Confidence interval mean not lies between the limits of original a5% Contidence interval and the remaining 19 - confidence interval means are lies in the fanges between the limits of contidence interval. Sample size (n = 160 The supporting Democrats tor medicare-formall (x)=136 Sample proportionat. (Surreyeed American Democrats) 0.85 95 -1960 1.940 I (1-6) 10.0553 E - 1-960* 140 136 (i) The point ethmate for p (11) At 95% Contidence levevel The critical value Z 2)2 = = 11.960 (1) The margin of error (E)=2x12 (0.85 X0.15 = 0.0553 (1) The confidence interval: Lower limit=-E=0.85-0.0553 = 0.7947 Uppes limit = $+ E= 0.85 +0.0553 -0.9053 The a5% CE is 0.7947 < p < 0.9053 (V) Interpretation at Cl. we are 95% Contident that the Tove proportion of all American democrats who support medicare - for-all lies in this interval. (il es between the limits of the calculated interval)