Question

A.7.3. A new cryogenic treatment on electronic audio signal transmitters claims to increase the signal-to- noise ratio (in decibels). In order to test this claim it is planned to draw a random sample of 5 untreated and 5 treated transmitters and measure the signal-to-noise ratio. Assume that these ratios each follows a normal distribution. Here's the data: untreated: 101.2, 101.5, 102.0, 101.0, 101.9 treated: 102.6, 101.9, 102.3, 101.9, 102.5 a) Is there evidence to suggest that the population variances are unequal? Use a 90% confidence interval to draw your conclusion (b) Construct a 95% confidence interval for ,ltreated-,untreated. (c) (unrelated question) In the treated sample above, construct a 95% confidence interval for σ2

Answer 1

73 d 2anaple 2 7S2 ダ22. s1 0.18

unve tee vendeur ees are ea une my 2 D 2. 102. 24 S n2 5

( . 5つ 、931

for the treatad caple , 25 4484 110143