Answer:
+/- 1.9983
Step-by-step explanation:
The critical values for a confidence interval for the population mean, with population standard deviation not known, are obtained from the student's t distribution.
The sample size is given as 64. The degrees of freedom will thus be;
sample size - 1 = 64 - 1 = 63
The confidence level is given as 95%. The level of significance will thus be;
100 - 95 = 5%.
The area in the right-tail will thus be 2.5%. Therefore, we looking for a t-value such that the area to its right is 2.5% and the degrees of freedom being 63. From the t-tables we have;
+/- 1.9983
Answer:
area of shaded portion = 226.09 m²
Step-by-step explanation:
area of circle = πr² = (3.14)(18.6²) = 1086.314 m²
area of 123° segment = (123/360)(1086.314) = 371.157 m²
cos 61.5° = height/18.6 = 8.875
height of triangle = 8.875 m
sin 61.5° = 1/2base/18.6 = 16.346, base = 32.692 m
base of triangle = 32.692 m
area of triangle = 1/2bh = 1/2(8.875)(32.692) = 145.071 m²
area of shaded portion = 371.157 - 145.071 = 226.09 m²
Answer:
c
Step-by-step explanation:
Answer:
- 1364
Step-by-step explanation:
The n th term of a geometric series is
= a
where a is the first term and r the common ratio
4
← is an n th term
with a = 4 and r = - 2
The sum to n terms of a geometric series is
= 
, thus
= 
= 
= 
= 
= - 1364
10% of 90 is 9. You can try cross multiplying.
