This is Question 2: Determine a 90%, 95% and 99% confidence interval for percent

Question

This is Question 2:

Determine a 90%, 95% and 99% confidence interval for percentage difference in “Zestimate” and selling price from question two. Interpret the intervals and explain why each of your intervals are different (which are wider and why?).

Price Sold Zestimate Higher/Lower Percentage $225,000 $254,514 $29517 - L -0.116 $302,000 $315,797 $13797 - L -0.044 $184,900 $182,583 $2317 - H 0.013 $250,000 $237,607 $12393 - H 0.052 $200,500 $200,545 $45 - L -0.0002 $277,000 $183,000 $94000 - H 0.514 $229,900 $233,615 $3715 - L -0.016 $263,250 $255,286 $7964 - H 0.031 $187,500 $186,726 $774 - H 0.004 $148,340 $146,843 $1497 - H 0.01 $231,000 $234,549 $3549 - L -0.015 $157,055 $197,534 $40479 - L -0.205 $139,900 $120,992 $18908 - H 0.156 $183,500 $185,936 $2436 - L -0.013 $340,000 $348,212 $8212 - L -0.024 $231,750 $232,079 $329 - L -0.001 $347,500 $348,557 $1057 - L -0.003 $342,150 $340,700 $1450 - H 0.004 $499,000 $482,415 $16585 - H 0.034 $377,500 $372,025 $5475 - H 0.015 $175,500 $177,108 $1608 - L -0.009 $415,000 $419,435 $4435 - L -0.011 $274,900 $268,667 $6233 - H 0.023 $248,800 $288,288 $39488 - L -0.137 $224,900 $189,330 $35570 - H 0.188 $199,900 $200,750 $850 - L -0.004 $239,900 $241,938 $2038 - L -0.008 $245,750 $261,476 $15726 - L -0.06 $278,000 $279,381 $1381 - L -0.005 $405,000 $404,156 $844 - H 0.002 $230,000 $220,563 $9437 - H 0.043

Explanation / Answer

90 % confidence interval

90 % confidence interval is ( -0.02, 0.05)

95 % confidence interval

95 % confidence interval (-0.03,0.05)

99% confidence in terval

99% confidence interval is (-0.04,0.07)

each of the interval is different because MArgin of error will be decideing the lower and upper limit interval for each confidence level.

Margin of error will be calculated based on the significance level (i.e 1-confidence coefficient), standard deviation and sample size. so if we change confidence coefficient value as 90 %,95% and 99% then according to the value of margin of error will change and give different lower and upper limit intervals.

90% - (-0.02,0.05)

95% - (-0.03,0.05)

99% - (-0.04,0.07)

99% cofidence interval lloks wider than 90% and 95 % becuase upper limit value is higher than the other two intervals

Margin of error formula =confidence(significant level,standard deviation,sample size)

Percentage Sample Size 31 Sample Mean 0.0134774 Standard Deviation 0.1165194 Confidence Coefficient 0.9 Significant level 0.1 Margin of error 0.03 Point Estimate 0.0134774 Lower Limit -0.02 Upper Limit 0.05

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.