Answer:
C
Step-by-step explanation:
Total of 40 cups and 25 of them are chocolate so the proportion for chocolate would be 25/40
Answer:
(130.08, 139.92)
Step-by-step explanation:
Given that:
Mean (m) = 135
Standard deviation (σ) = 30
Sample size (n) = 100
α = 90%
The confidence interval value is obtained using the relation:
Mean ± Zcritical * (standard deviation / sqrt(n))
Zcritical at 90% = 1.64
standard deviation / sqrt(n) = 30 / sqrt(100)
= 30 / 10 = 3
Hence,
135 ± 1.64 * (3)
Lower limit : 135 - (1.64 * 3) = 130.08
Upper limit : 135 + (1.64 * 3) = 139.92
Hence,
Confidence interval = (130.08, 139.92)
