Petra groaned and put her head in her hands, covering her face. "I don't understand!" she exclaimed to her tutor. Because she wasn't doing so well in statistics, her parents sought out a tutor to help her get the material she was learning. She wasn't really into the idea at first, but she had to agree that a tutor was what she needed. So, when her parents found her one, she was a little relieved because at least somebody would help her understand all these numbers and stats symbols. However, what her parents didn't mention was that her tutor would show up every other weekend to help her. There goes most of her free days.
"And what don't you understand?" Levi asked. Levi was a year older than Petra, went to her high school, and was great when it came to anything math related. He was the one that was tutoring her. Though Petra didn't mind Levi, (he was an okay guy, he smelled nice, and was very good looking in her eyes. But that would never distract her) she hated how he would teach her. He just couldn't simplify things well.
"I don't understand any of it! It's already halfway through our first semester and I'm struggling. Shouldn't the material be easy in the beginning?" A rhetorical question, but Levi always had an answer.
"Yes. But I'm trying to explain it to you," he took Petra's homework and started marking her work lightly in pencil, "you see this?" Petra nodded. "Okay, well this is a Z-test for the mean. This is probably the first hypothesis test you learned. Correct?" She nodded again. "And how do we know that it's a Z-test?"
Petra leaned closer to Levi and squinted her eyes. "Uhm… because… you… said so?"
Levi sighed and tapped his pencil at what looked like a sideways 6. "This is sigma. We know it's a Z-test because sigma is known. And how else do we know that it's Z?"
She laid her head on Levi's shoulder. She could hear him mutter something along the lines of 'lazy girl', but she shrugged it's Levi and she expects those types of comments from him. "Because…" she trailed off again and began thinking about what Mr. Smith taught that day. "Because… it says… population standard deviation?"
Levi dropped his pencil, crossed his arms, and gave her a small smile. "Exactly."
Petra beamed and picked her head up from his shoulder and let out a small 'yes!' and extended her arm to give Levi a high five. He brought out his hand and swung, but purposely missed and slammed his hand on the desk instead, making sure not to slam it too hard. She jumped and looked down at her unfinished homework.
Levi tapped on her homework with his finger and wagged his other index finger at her, "No celebrating. Celebrating is for later, when you actually finish your work this time."