Answer:
d
Step-by-step explanation:
Area of the inner circle = 3^2 π = 9 π
total area = 10^2 π = 100π
area of the shaded region
100π - 9 π = 91 π
Answer:
95% confidence interval for the difference between the average mass of eggs in small and large nest is between a lower limit of 0.81 and an upper limit of 2.39.
Step-by-step explanation:
Confidence interval is given by mean +/- margin of error (E)
Eggs from small nest
Sample size (n1) = 60
Mean = 37.2
Sample variance = 24.7
Eggs from large nest
Sample size (n2) = 159
Mean = 35.6
Sample variance = 39
Pooled variance = [(60-1)24.7 + (159-1)39] ÷ (60+159-2) = 7619.3 ÷ 217 = 35.11
Standard deviation = sqrt(pooled variance) = sqrt(35.11) = 5.93
Difference in mean = 37.2 - 35.6 = 1.6
Degree of freedom = n1+n2 - 2 = 60+159-2 = 217
Confidence level = 95%
Critical value (t) corresponding to 217 degrees of freedom and 95% confidence level is 1.97132
E = t×sd/√(n1+n2) = 1.97132×5.93/√219 = 0.79
Lower limit = mean - E = 1.6 - 0.79 = 0.81
Upper limit = mean + E = 1.6 + 0.79 = 2.39
95% confidence interval for the difference in average mass is (0.81, 2.39)
158.71 rounded to the nearest ten dollars would be $160.00
then to estimate 10% since 10% starts with a 1, just remove the zero from both numbers
so 160 becomes 16
the tip would be $16
Correct Question:
John works as a tutor for $12 an hour and as a waiter for $8 an hour. This month, he worked a combined total of 86 hours at his two jobs.
Let be the number of hours John worked as a tutor this month. Write an expression for the combined total dollar amount he earned this month.
Answer:
Total hours = 86
Let t is the hours he spent on tutoring
then (86-t) is hours spent on waiting
Let Y is the total amount in dollars which is required .
Now;
y = (tutoring hours x 12$) + (waiting hours x 8$)
Y = 12t + 8(86-t)
Answer:
x = 39.1
Step-by-step explanation:
mean = average off all the numbers =
sum of the numbers / amount of numbers.
35 = sum of the #'s / # of #'s
35 = 100.9 + x / 4
35 × 4 = 100.9 + x / 4 × 4
140 = 100.9 + x
140 – 100.9 = 100.9 + x – 100.9
39.1 = x
x = 39.1
