<span>204
First, lookup a standard normal table and see what the z-score is for 0.025 (one half of 100% - 95%) to allow for equal sized tails. You should find that the z-score is 1.96. That means that 95% of the time, the value should be within 1.96 standard deviations of the mean. Now let's calculate the standard deviation.
800 is 800 - 1200 = -400 to the left of the mean of 1200.
1600 is 1600 - 1200 = 400 to the right of the mean of 1200.
So we are an equal distance of 400 on both sides of the mean. And we know from the z-score of 1.96, that we're 1.96 standard deviations from the mean. So a little division will give us the standard deviation. Which is:
400 / 1.96 = 204.0816327
So the standard deviation of the light bulbs is 204</span>
It is 48 cm together because mutiply it
Answer:Triangle A: 38 degrees
Triangle B: Unknown (not enough information)
Triangle C: Unknown (not enough information)
Triangle D: 70 degrees
Triangle E: 40 degrees
Step-by-step explanation:
Answer:
72.73% probability of selecting a girl, given the flip resulted inheads
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
Coin resulted in heads
Student is selected at random from a class of six boys and sixteen girls.
Desired outcomes:
16 girls, so 
Total outcomes:
16+6 = 22, that is, 22 students, so 
Probability:
72.73% probability of selecting a girl, given the flip resulted inheads
Answer:
Step-by-step explanation:
discriminant = (-13)² - 4·2·15 = 49
discriminant > 0 so there are two real roots
